MIT Latest News

Subscribe to MIT Latest News feed
MIT News is dedicated to communicating to the media and the public the news and achievements of the students, faculty, staff and the greater MIT community.
Updated: 1 hour 36 min ago

MIT-Japan Program establishes the Patricia Gercik Memorial Fund

Thu, 08/19/2021 - 1:30pm

The MIT-Japan Program has announced the establishment of the Patricia Gercik Memorial Fund. The endowed fund will provide supplemental stipends to students seeking internships in Japan.

Gercik served as managing director of the MIT-Japan Program for almost three decades and introduced hundreds of MIT students to Japanese culture, history, and in-country internship experiences.

MIT-Japan is a part of (and was the prototype for) the MIT International Science and Technology Initiatives (MISTI) — the Institute’s pioneering global internship program. Gercik simultaneously served as associate director of MISTI, which is among the largest and most renowned programs at the Center for International Studies (CIS).

“Pat was one of a kind — truly a force of nature. In her tireless efforts to facilitate collaboration with Japan at MIT, Pat blazed new paths in international education and truly epitomized the MIT spirit of innovation. She touched so many students so deeply, and we are proud to have worked closely with many of them to establish this endowed fund in her memory,” says Richard Samuels, the Ford International Professor of Political Science, director of CIS, and the founding director of the MIT-Japan Program.

Gercik’s early and sustained enthusiastic leadership of the MIT-Japan Program clearly demonstrated this commitment. Her knowledge of all things Japanese was vast and her passion for the country was infectious.

Born to a British mother and a Russian father who relocated to Kobe, Japan, in the 1930s, Gercik lived a Japanese childhood. She recalled “confronting” U.S. soldiers during the Occupation and wandering through the black markets of a reconstructing Tokyo in her autobiographical novel, “The Outsider.” She also authored “On Track with the Japanese,” an interactive guide based on the experiences of program interns that provides insights to non-natives into Japan’s complex society.

Informed by her own experiences in Japan, she thoughtfully matched students studying a wide range of disciplines with challenging internships that would encourage them to grow in unexpected ways. She had an uncanny knack for clearly conveying the nuance and subtlety of Japanese communication to those who weren’t familiar with Japan. For many of her students, she instilled a lifelong love of and connection to a country that, without her guidance, could have seemed mysterious and unknowable.

In 2010, the Institute recognized her extraordinary work by bestowing her with an MIT Excellence Award. She was described by her nominators as having “a passionate belief in our mission to help MIT students become informed global citizens” and as “a visionary leader whose spontaneous enthusiasm and zeal for life can barely be contained.”

After battling a long illness, Gercik died on Sept. 17, 2019.

“When we learned the heartbreaking news about Pat, we really wanted to do something in her honor. We — and especially her former students — could think of no better tribute to Pat’s life and contributions to MIT than to establish a memorial fund in her honor,” says Christine Pilcavage, managing director of the MIT-Japan Program.

Alumni of the MIT-Japan Program were instrumental in raising the initial seed money and making the memorial fund a reality. Their dream, now realized, was to endow the fund in perpetuity so that her legacy continues at MIT.

The inaugural recipients of the Patricia Gercik Memorial Fund will be announced in spring 2022 with the hope of resuming in-country internships by that summer. Travel restrictions for MIT students due to the Covid-19 pandemic have paused travel to Japan since spring 2020.

The MIT-Japan Program looks forward to hosting a ceremony next spring to honor Gercik and celebrate the first students to receive this award.

To learn more about Gercik, including quotes from her former students and information on how to donate to the Patricia Gercik Memorial Fund, please visit the MIT-Japan Program’s Patricia Gercik memorial webpage.

A peculiar state of matter in layers of semiconductors

Thu, 08/19/2021 - 12:00pm

Scientists around the world are developing new hardware for quantum computers, a new type of device that could accelerate drug design, financial modeling, and weather prediction. These computers rely on qubits, bits of matter that can represent some combination of 1 and 0 simultaneously. The problem is that qubits are fickle, degrading into regular bits when interactions with surrounding matter interfere. But new research at MIT suggests a way to protect their states, using a phenomenon called many-body localization (MBL).

MBL is a peculiar phase of matter, proposed decades ago, that is unlike solid or liquid. Typically, matter comes to thermal equilibrium with its environment. That’s why soup cools and ice cubes melt. But in MBL, an object consisting of many strongly interacting bodies, such as atoms, never reaches such equilibrium. Heat, like sound, consists of collective atomic vibrations and can travel in waves; an object always has such heat waves internally. But when there’s enough disorder and enough interaction in the way its atoms are arranged, the waves can become trapped, thus preventing the object from reaching equilibrium.

MBL had been demonstrated in “optical lattices,” arrangements of atoms at very cold temperatures held in place using lasers. But such setups are impractical. MBL had also arguably been shown in solid systems, but only with very slow temporal dynamics, in which the phase’s existence is hard to prove because equilibrium might be reached if researchers could wait long enough. The MIT research found a signatures of MBL in a “solid-state” system — one made of semiconductors — that would otherwise have reached equilibrium in the time it was watched.

“It could open a new chapter in the study of quantum dynamics,” says Rahul Nandkishore, a physicist at the University of Colorado at Boulder, who was not involved in the work.

Mingda Li, the Norman C Rasmussen Assistant Professor Nuclear Science and Engineering at MIT, led the new study, published in a recent issue of Nano Letters. The researchers built a system containing alternating semiconductor layers, creating a microscopic lasagna — aluminum arsenide, followed by gallium arsenide, and so on, for 600 layers, each 3 nanometers (millionths of a millimeter) thick. Between the layers they dispersed “nanodots,” 2-nanometer particles of erbium arsenide, to create disorder. The lasagna, or “superlattice,” came in three recipes: one with no nanodots, one in which nanodots covered 8 percent of each layer’s area, and one in which they covered 25 percent.

According to Li, the team used layers of material, instead of a bulk material, to simplify the system so dissipation of heat across the planes was essentially one-dimensional. And they used nanodots, instead of mere chemical impurities, to crank up the disorder.

To measure whether these disordered systems are still staying in equilibrium, the researchers measured them with X-rays. Using the Advanced Photon Source at Argonne National Lab, they shot beams of radiation at an energy of more than 20,000 electron volts, and to resolve the energy difference between the incoming X-ray and after its reflection off the sample’s surface, with an energy resolution less than one one-thousandth of an electron volt. To avoid penetrating the superlattice and hitting the underlying substrate, they shot it at an angle of just half a degree from parallel.

Just as light can be measured as waves or particles, so too can heat. The collective atomic vibration for heat in the form of a heat-carrying unit is called a phonon. X-rays interact with these phonons, and by measuring how X-rays reflect off the sample, the experimenters can determine if it is in equilibrium.

The researchers found that when the superlattice was cold — 30 kelvin, about -400 degrees Fahrenheit — and it contained nanodots, its phonons at certain frequencies remained were not in equilibrium.

More work remains to prove conclusively that MBL has been achieved, but “this new quantum phase can open up a whole new platform to explore quantum phenomena,” Li says, “with many potential applications, from thermal storage to quantum computing.”

To create qubits, some quantum computers employ specks of matter called quantum dots. Li says quantum dots similar to Li’s nanodots could act as qubits. Magnets could read or write their quantum states, while the many-body localization would keep them insulated from heat and other environmental factors.

In terms of thermal storage, such a superlattice might switch in and out of an MBL phase by magnetically controlling the nanodots. It could insulate computer parts from heat at one moment, then allow parts to disperse heat when it won’t cause damage. Or it could allow heat to build up and be harnessed later for generating electricity.

Conveniently, superlattices with nanodots can be constructed using traditional techniques for fabricating semiconductors, alongside other elements of computer chips. According to Li, “It’s a much larger design space than with chemical doping, and there are numerous applications.”

“I am excited to see that signatures of MBL can now also be found in real material systems," says Immanuel Bloch, scientific director at the Max-Planck-Institute of Quantum Optics, of the new work. “I believe this will help us to better understand the conditions under which MBL can be observed in different quantum many-body systems and how possible coupling to the environment affects the stability of the system. These are fundamental and important questions and the MIT experiment is an important step helping us to answer them.”

Funding was provided by the U.S. Department of Energy’s Basic Energy Sciences program’s Neutron Scattering Program.

MIT Libraries staff honored with 2021 Infinite Mile Awards

Wed, 08/18/2021 - 4:00pm

The MIT Libraries celebrated the outstanding contributions of its employees in June with its 2021 Infinite Mile Awards ceremony. The online ceremony had a summer camp theme and featured an art and crafts showcase, funny pet photos, and recorded performances by the libraries' band, The Dust Jackets. 

Awards were presented to individuals and teams in the categories listed below; recipients are listed along with excerpts from the award presentations.

Bringing out the best

Serving as interim music librarian while also continuing to lead the Libraries’ Community Building and Engagement program, Nina Davis-Millis is known for dreaming big. The creator of the Institute-wide program MIT Reads, she “had the creative vision to recognize the power of a community built around books, reading, and conversation,” according to one colleague. Considered a leader and a mentor, Davis-Millis will inevitably respond to a new idea with, “How can we make it work?”

Innovation, creativity, and problem solving

The Distinctive Collections Restart Team not only had to set up a pop-up workspace in a new building, they also had to build new workflows on a new request system, all while juggling the challenges that Covid restrictions threw their way. For inventing new ways of providing the community remote access to materials and services that were previously only available physically, this award went to Ashlynn August, Mattie Clear, Myles Crowley, Jana Dambrogio, Neal Johnson, Grace Johnson-DeBaufre, Ayako Letizia, Jess Myers, and Jenn Morris.

Results, outcome, and productivity

The support staff of Lewis Music Library and the department of Information Delivery and Library Access was instrumental in planning the Libraries’ return to on-campus work. “They rolled with a constantly changing landscape as the state, MIT, and the Libraries navigated the Covid crisis, and did so with a thoughtful and patron-centered focus,” said one colleague. Team members include Moses Carr, Astride Chery, Ashley Clark, Lara Day, Jim Eggleston, Cate Gallivan, Allyson Harper-Nixon, Jessica Holmes, Samuel Hong, S. Kohler, Forrest Larson, Georgina Lewis, Maura Liggio, Donald Long, Howard Martin, Jacky Martin, Alyssa Maynard, Jessa Modell, Jonathan Paul, Daniel Pribble, Jessica Shrey, Pixie Rose, Maria Walsh, Jaclyn Wilson, and Hannah Winkler.

Unsung heroes

Hailed for his focus on providing the best possible service to library patrons, Access Services Assistant Jonathan Paul is known for his reliability, kindness, and easy communication. Praised for being warm and open when interacting with student employees, Paul was also recognized for his inquisitiveness and eagerness to learn, taking classes every semester to increase his knowledge and skills. 

When a gargantuan project needed a guiding hand, head of Data and Specialized Services Howard Silver was willing to dive right in. He brought his prodigious knowledge of library services and understanding of construction, logistics, operations, and architecture to the Hayden Library and Building 14 Courtyard renovation projects. Lauded for being “reasonable, kind, and calm,” Silver deftly coordinated the work of many internal and external stakeholders to help get the renovation over the finish line.

Christine Moulen “Good Citizen” Award

Known for being an excellent listener and genuinely interested in others and their welfare, Human Resources Assistant Sam Locke was called “a rock of support within chaos, particularly through the pandemic.” One nominator noted, “They are constantly trying to spread positivity and cheer even in the most stressful of situations.” As driven as they are generous, Locke handles difficult situations with graceful professionalism, has a flair for problem-solving, and takes initiative, shepherding work along when others aren’t sure where to start.

Magnets could offer better control of prosthetic limbs

Wed, 08/18/2021 - 2:00pm

For people with amputation who have prosthetic limbs, one of the greatest challenges is controlling the prosthesis so that it moves the same way a natural limb would. Most prosthetic limbs are controlled using electromyography, a way of recording electrical activity from the muscles, but this approach provides only limited control of the prosthesis.

Researchers at MIT’s Media Lab have now developed an alternative approach that they believe could offer much more precise control of prosthetic limbs. After inserting small magnetic beads into muscle tissue within the amputated residuum, they can precisely measure the length of a muscle as it contracts, and this feedback can be relayed to a bionic prosthesis within milliseconds.

In a new study appearing today in Science Robotics, the researchers tested their new strategy, called magnetomicrometry (MM), and showed that it can provide fast and accurate muscle measurements in animals. They hope to test the approach in people with amputation within the next few years.

“Our hope is that MM will replace electromyography as the dominant way to link the peripheral nervous system to bionic limbs. And we have that hope because of the high signal quality that we get from MM, and the fact that it’s minimally invasive and has a low regulatory hurdle and cost,” says Hugh Herr, a professor of media arts and sciences, head of the Biomechatronics group in the Media Lab, and the senior author of the paper.

Cameron Taylor, an MIT postdoc, is the lead author of the study. Other authors include MIT postdoc Shriya Srinivasan, MIT graduate student Seong Ho Yeon, Brown University professor of ecology and evolutionary biology Thomas Roberts, and Brown postdoc Mary Kate O’Donnell.

Precise measurements

With existing prosthetic devices, electrical measurements of a person’s muscles are obtained using electrodes that can be either attached to the surface of the skin or surgically implanted in the muscle. The latter procedure is highly invasive and costly, but provides somewhat more accurate measurements. However, in either case, electromyography (EMG) offers information only about muscles’ electrical activity, not their length or speed.

“When you use control based on EMG, you're looking at an intermediate signal. You’re seeing what the brain is telling the muscle to do, but not what the muscle is actually doing,” Taylor says.

The new MIT strategy is based on the idea that if sensors could measure what muscles are doing, those measurements would offer more precise control of a prosthesis. To achieve, that, the researchers decided to insert pairs of magnets into muscles. By measuring how the magnets move relative to one another, the researchers can calculate how much the muscles are contracting and the speed of contraction.

Two years ago, Herr and Taylor developed an algorithm that greatly reduced the amount of time needed for sensors to determine the positions of small magnets embedded in the body. This helped them to overcome one of the major hurdles to using MM to control prostheses, which was the long lag-time for such measurements.

In the new Science Robotics paper, the researchers tested their algorithm’s ability to track magnets inserted in the calf muscles of turkeys. The magnetic beads they used were 3 millimeters in diameter and were inserted at least 3 centimeters apart — if they are closer than that, the magnets tend to migrate toward each other.

Using an array of magnetic sensors placed on the outside of the legs, the researchers found that they were able to determine the position of the magnets with a precision of 37 microns (about the width of a human hair), as they moved the turkeys’ ankle joints. These measurements could be obtained within three milliseconds.

For control of a prosthetic limb, these measurements could be fed into a computer model that predicts where the patient’s phantom limb would be in space, based on the contractions of the remaining muscle. This strategy would direct the prosthetic device to move the way that the patient wants it to, matching the mental picture that they have of their limb position.

“With magnetomicrometry, we’re directly measuring the length and speed of the muscle,” Herr says. “Through mathematical modeling of the entire limb, we can compute target positions and speeds of the prosthetic joints to be controlled, and then a simple robotic controller can control those joints.”

Muscle control

Within the next few years, the researchers hope to do a small study in human patients who have amputations below the knee. They envision that the sensors used to control the prosthetic limbs could be placed on clothing, attached to the surface of the skin, or affixed to the outside of a prosthesis.

MM could also be used to improve the muscle control achieved with a technique called functional electrical stimulation, which is now used to help restore mobility in people with spinal cord injuries. Another possible use for this kind of magnetic control would be to guide robotic exoskeletons, which can be attached to an ankle or another joint to help people who have suffered a stroke or developed other kinds of muscle weakness.

“Essentially the magnets and the exoskeleton act as an artificial muscle that will amplify the output of the biological muscles in the stroke-impaired limb,” Herr says. “It’s like the power steering that’s used in automobiles.”

Another advantage of the MM approach is that it is minimally invasive. Once inserted in the muscle, the beads could remain in place for a lifetime without needing to be replaced, Herr says.

The research was funded by the Salah Foundation, the MIT Media Lab Consortia, the National Institutes of Health, and the National Science Foundation.

High-speed camera captures a water jet’s splashy impact as it pierces a droplet

Wed, 08/18/2021 - 12:00am

Squirting a jet of water through a drop of liquid may sound like idle fun, but if done precisely, and understood thoroughly, the splashy exercise could help scientists identify ways to inject fluids such as vaccines through skin without using needles.

That’s the motivation behind a new study by engineers at MIT and the University of Twente in the Netherlands. The study involves firing small jets of water through many kinds of droplets, hundreds of times over, using high-speed cameras to capture each watery impact. The team’s videos are reminiscent of the famous strobe-light photographs of a bullet piercing an apple, pioneered by MIT’s Harold “Doc” Edgerton.

Edgerton’s images captured sequential images of a bullet being shot through an apple, in explosive detail. The MIT team’s new videos, of a water jet fired through a droplet, reveal surprisingly similar impact dynamics. As the droplets in their experiments are transparent, the researchers were also able to track what happens inside a droplet as a jet is fired through.

Based on their experiments, the researchers developed a model that predicts how a fluid jet will impact a droplet of a certain viscosity and elasticity. As human skin is also a viscoelastic material, they say the model may be tuned to predict how fluids could be delivered through the skin without the use of needles.

“We want to explore how needle-free injection can be done in a way that minimizes damage to the skin,” says David Fernandez Rivas, a research affiliate at MIT and professor at the University of Twente. “With these experiments, we are getting all this knowledge, to inform how we can create jets with the right velocity and shape to inject into skin.”

Rivas and his collaborators, including Ian Hunter, the George N. Hatsopoulos Professor in Thermodynamics at MIT, have published their results in the journal Soft Matter.

Penetrating pores

Current needle-free injection systems use various means to propel a drug at high speed through the skin’s natural pores. For instance, MIT spinout Portal Instruments, which has sprung from Hunter’s group, centers on a design that uses an electromagnetic actuator to eject thin streams of medicine through a nozzle at speeds high enough to penetrate through skin and into the underlying muscle.

Hunter is collaborating with Rivas on a separate needle-free injection system to deliver smaller volumes into shallower layers of the skin, similar to the depths at which tattoos are inked.

“This regime poses different challenges but also gives opportunities for personalized medicine,” says Rivas, who says medicines such as insulin and certain vaccines can be effective when delivered in smaller doses to the skin’s superficial layers.

Rivas’ design uses a low-power laser to heat up a microfluidic chip filled with fluid. Similar to boiling a kettle of water, the laser creates a bubble in the fluid that pushes the liquid through the chip and out through a nozzle, at high speeds.

Rivas has previously used transparent gelatin as a stand-in for skin, to identify speeds and volumes of fluid the system might effectively deliver. But he quickly realized that the rubbery material is difficult to precisely reproduce.

“Even in the same lab and following the same recipes, you can have variations in your recipe, so that if you try to find the critical stress or velocity your jet must have to get through skin, sometimes you have values one or two magnitudes apart,” Rivas says.

Beyond the bullet

The team decided to study in detail a simpler injection scenario: a jet of water, fired into a suspended droplet of water. The properties of water are better known and can be more carefully calibrated compared to gelatin.

In the new study, the team set up a laser-based microfluidic system and fired off thin jets of water at a single water droplet, or “pendant,” hanging from a vertical syringe. They varied the viscosity of each pendant by adding certain additives to make it as thin as water, or thick like honey. They then recorded each experiment with high-speed cameras.

Playing the videos back at 50,000 frames per second, the researchers were able to measure the speed and size of the liquid jet that punctured and sometimes pierced straight through the pendant. The experiments revealed interesting phenomena, such as instances when a jet was dragged back into a pendant, due to the pendant’s viscoelasticity. At times the jet also generated air bubbles as it pierced the pendant.

“Understanding these phenomena is important because if we are injecting into skin in this way, we want to avoid, say, bringing air bubbles into the body,” Rivas says.

The researchers looked to develop a model to predict the phenomena they were seeing in the lab. They took inspiration from Edgerton’s bullet-pierced apples, which appeared similar, at least outwardly, to the team’s jet-pierced droplets.

They started with a straightforward equation to describe the energetics of a bullet fired through an apple, adapting the equation to a fluid-based scenario, for instance by incorporating the effect of surface tension, which has no effect in a solid like an apple but is the main force that can keep a fluid from breaking apart. They worked under the assumption that, like a bullet, the fired jet would maintain a cylindrical shape. They found this simple model roughly approximated the dynamics they observed in their experiments.

But the videos clearly showed that the jet’s shape, as it penetrated a pendant, was more complex than a simple cylinder. So, the researchers developed a second model, based on a known equation by physicist Lord Rayleigh, that describes how the shape of a cavity changes as it moves through a liquid. They modified the equation to apply to a liquid jet moving through a liquid droplet, and found that this second model produced a more accurate representation of what they observed.

“This new method of generating high-velocity microdroplets is very important to the future of needle-free drug delivery,” Hunter says. “An understanding of how these very fast-moving microdroplets interact with stationary liquids of different viscosities is an essential first step to modeling their interaction with a wide range of tissue types.”

The team plans to carry out more experiments, using pendants with properties even more like those of skin. The results from these experiments could help fine-tune the  models to narrow in on the optimal conditions for injecting drugs, or even inking tattoos, without using needles.

This research was supported in part by the European Research Council under the European Union Horizon 2020 Research and Innovation Programme.

Bridging the gap between education and employment: Community college and beyond

Tue, 08/17/2021 - 6:00pm

The pandemic underscored an urgent need: The best-educated workers are prospering, but too many others are being left behind. To address this challenge, community colleges can be rich resources for educating the higher-skilled workers that industry is now demanding. However, schools, working with employers and policymakers, must do more to bridge the gap between education and employment.

This July, in a statewide effort to build new education models for advanced skills, MIT Open Learning and MassBridge hosted “Bridging the Education/Workforce Gap: Community College and Beyond,” a two-day conference with thought leaders from all parts of the education-workforce equation to explore how to expand and create new training opportunities that prepare students for quality jobs. Building on new models discussed in a recent MIT study (MassBridge Advanced Manufacturing Education Benchmark Report), speakers shared further ideas on how to bridge that gap between education and employment across many different sectors.

Throughout the conference, some common themes emerged:

  • The workforce needs agile learners who can upskill easily.
  • Industry needs change rapidly, so training programs need to adapt accordingly.
  • Partnerships with employers in the industry are key.
  • Courses, apprenticeships, and credentialing need to be accessible to all learners.

Day 1: Education perspectives

On the first day of programming, professionals from community colleges, state government, and industry recognized the growing need for adaptable workforce training programs at both the entry level and the incumbent worker level, which will require strong partnerships between educational programs and employers. George Westerman, senior lecturer at the MIT Sloan School of Management and a principal research scientist at J-WEL Workforce Learning, says “We need a new model for employers to help create the workers they need, rather than trying to find them.” A flexible hybrid online/in-person model would allow a wider range of students to access and complete these programs. Training programs should emphasize “human skills” that workers will still be able to leverage even as hard skills evolve.

In “The Changing Face of Community College Education,” panelists who work at community colleges discussed the growing demand for incumbent worker training and fast-tracked entry-level workforce training. Repackaging curricula with tangible milestones such as “stackable credentials”  would accelerate the path to a degree for part-time students, they said. Focusing on “credentials of value” can embed employer needs from local industry in courses.

Moderated by Bob LePage, Massachusetts assistant secretary for career education, a panel on the role of education policy focused on the opportunities to rebuild and modernize the education system. The pandemic has shown that a hybrid education approach could be an equitable strategy that combines the best of digital access and hands-on activities to accelerate student learning. Beyond the classroom, schools need scalable work-based learning opportunities beyond registered apprentices. Federal and state policymakers are also looking to embed industry partnerships into the traditional degree model, speakers said.

In “A Cross-industry Look at Education Needs,” panelists from Mass Tech College and University, Beth Israel Deaconess Medical Center, the University of Massachusetts, and the University of Pittsburgh Medical Center discussed the challenges of finding qualified candidates for technical jobs. They envisioned a system for incentivizing these difficult-to-fill positions by partnering with community colleges to offer short-term training for lower-wage workers. By training the existing workforce, employers can better evolve to fit their own needs.

A keynote presentation from Bill Bonvillian, senior director of special projects at MIT Open Learning and lecturer at MIT, and Sanjay Sarma, vice president for open learning, focused on the high labor nonparticipation rates that have been building over the last 15 years and exacerbated by the pandemic. Recent reports show millions of higher-skilled jobs are going unfilled because we lack the workforce education system to train those who can fill them. The labor market information chain is broken: Workers don’t know what skills they need, educators don’t know what skills to educate for, and employers don’t know what skills workers have. “The social contract of universities has to change,” Sarma said. “Ideally, such a contract would provide “a holistic education to people who need it in the workforce.”

Drawing from Bonvillian and Sarma's recent book "Workforce Education," Bonvillian offered recommendations for new delivery models of training, such as breaking down the work/learning barrier with more apprenticeships; creating “trifecta” programs at community colleges that reach high school students, community college students, and incumbent workers; implementing short courses that lead to certificates and degrees for students who are already in the workforce and have time restraints; and integrating federal programs at the state level. Bonvillian said, “Designing programs that complement each other ... blurring the line between degrees and credentials, filling gaps where Pell grants don't help on workforce needs — these are all programs that have come right out of those combined education-industry efforts.”

Day 2: Industry, government, and student perspectives

Workers of the future will need to be trained in digital literacy, hands-on abilities, and critical thinking. Speakers on the second day of programming indicated a strong drive, persistence, and curiosity from community college students that can be fostered through targeted training programs.

In the panel “Up and Coming,” MIT mechanical engineering lecturer John Liu moderated a conversation with a group of current and former community college students who returned to school after a stint in the workforce to pursue training in another field. Their motivations ranged from pursuing their passions to helping others to creating a more stable future for themselves. One panelist, Mussie Demisse, was a former Bunker Hill Community College student who went on to graduate with a bachelor’s degree from MIT. Demisse said the MassHire program, which supports student success through state funding and industry involvement via individual coaching and internships, “aligned their goals with mine for my betterment, and that made it easier for me to align my goals with them.”

Keynote speaker Celeste Carter, lead program director for advanced technological education at the National Science Foundation (NSF), shared how the NSF developed a program that looked at innovative strategies to educate the skilled technical workforce. Carter said communication with students is hugely important to training programs. “There’s a lot of curiosity, a lot of persistence, a lot of really smart people at two-year institutions. We need to take advantage of it,” she said.

In a panel on statewide agency and collaboration, statewide education leaders who work for different institutions in different states shared how they have seen similar successes through partnerships, listening, and flexibility. Panelists said it’s important to have a flexible program structure that can adapt to these evolving needs of employers and students. Amy Firestone of Apprentice Carolina and South Carolina’s Technical College System shared how their “3D process” (which stands for “discovery, design, and delivery”) informed their program.

Crossing organizational boundaries

Across two days of panel discussions, educators, policymakers, industry leaders, and students spoke to the success of partnerships between educational institutions and employers. If employers have a vested interest in the outcomes of training programs, students will be trained with the current needs of their industries in mind, and will be better prepared for the workforce upon graduation, they said.

"One word we heard a lot during this conference is “partnership,” and that’s so important,” says Westerman. “Because we have a gap, and you can't cross this gap on your own. We all know that crossing organizational boundaries is an unnatural act, and so we all have to find ways to get across there."

Smarter regulation of global shipping emissions could improve air quality and health outcomes

Tue, 08/17/2021 - 6:00pm

Emissions from shipping activities around the world account for nearly 3 percent of total human-caused greenhouse gas emissions, and could increase by up to 50 percent by 2050, making them an important and often overlooked target for global climate mitigation. At the same time, shipping-related emissions of additional pollutants, particularly nitrogen and sulfur oxides, pose a significant threat to global health, as they degrade air quality enough to cause premature deaths.

The main source of shipping emissions is the combustion of heavy fuel oil in large diesel engines, which disperses pollutants into the air over coastal areas. The nitrogen and sulfur oxides emitted from these engines contribute to the formation of PM2.5, airborne particulates with diameters of up to 2.5 micrometers that are linked to respiratory and cardiovascular diseases. Previous studies have estimated that PM2.5  from shipping emissions contribute to about 60,000 cardiopulmonary and lung cancer deaths each year, and that IMO 2020, an international policy that caps engine fuel sulfur content at 0.5 percent, could reduce PM2.5 concentrations enough to lower annual premature mortality by 34 percent.

Global shipping emissions arise from both domestic (between ports in the same country) and international (between ports of different countries) shipping activities, and are governed by national and international policies, respectively. Consequently, effective mitigation of the air quality and health impacts of global shipping emissions will require that policymakers quantify the relative contributions of domestic and international shipping activities to these adverse impacts in an integrated global analysis.

A new study in the journal Environmental Research Letters provides that kind of analysis for the first time. To that end, the study’s co-authors — researchers from MIT and the Hong Kong University of Science and Technology — implement a three-step process. First, they create global shipping emission inventories for domestic and international vessels based on ship activity records of the year 2015 from the Automatic Identification System (AIS). Second, they apply an atmospheric chemistry and transport model to this data to calculate PM2.5 concentrations generated by that year’s domestic and international shipping activities. Finally, they apply a model that estimates mortalities attributable to these pollutant concentrations.

The researchers find that approximately 94,000 premature deaths were associated with PM2.5 exposure due to maritime shipping in 2015 — 83 percent international and 17 percent domestic. While international shipping accounted for the vast majority of the global health impact, some regions experienced significant health burdens from domestic shipping operations. This is especially true in East Asia: In China, 44 percent of shipping-related premature deaths were attributable to domestic shipping activities.

“By comparing the health impacts from international and domestic shipping at the global level, our study could help inform decision-makers’ efforts to coordinate shipping emissions policies across multiple scales, and thereby reduce the air quality and health impacts of these emissions more effectively,” says Yiqi Zhang, a researcher at the Hong Kong University of Science and Technology who led the study as a visiting student supported by the MIT Joint Program on the Science and Policy of Global Change.

In addition to estimating the air-quality and health impacts of domestic and international shipping, the researchers evaluate potential health outcomes under different shipping emissions-control policies that are either currently in effect or likely to be implemented in different regions in the near future.

They estimate about 30,000 avoided deaths per year under a scenario consistent with IMO 2020, an international regulation limiting the sulfur content in shipping fuel oil to 0.5 percent — a finding that tracks with previous studies. Further strengthening regulations on sulfur content would yield only slight improvement; limiting sulfur content to 0.1 percent reduces annual shipping-attributable PM2.5-related premature deaths by an additional 5,000. In contrast, regulating nitrogen oxides instead, involving a Tier III NOx Standard would produce far greater benefits than a 0.1-percent sulfur cap, with 33,000 further avoided deaths.

“Areas with high proportions of mortalities contributed by domestic shipping could effectively use domestic regulations to implement controls,” says study co-author Noelle Selin, a professor at MIT’s Institute for Data, Systems and Society and Department of Earth, Atmospheric and Planetary Sciences, and a faculty affiliate of the MIT Joint Program. “For other regions where much damage comes from international vessels, further international cooperation is required to mitigate impacts.”

3 Questions: Martin Schmidt on MIT’s Strategic Action Plan for Diversity, Equity, and Inclusion

Tue, 08/17/2021 - 8:00am

Work on MIT’s Strategic Action Plan for Diversity, Equity, and Inclusion started last fall, and the plan’s first draft was released in late March 2020. Powered by inputs and feedback from three dozen community engagement sessions and a steady stream of email responses from students, staff, faculty, postdocs, alumni, and others, the plan is being revised and updated over the summer with hopes for a fall release. The development of the strategic plan is being led by Institute Community and Equity Officer John Dozier, along with Deputy ICEO Maryanne Kirkbride and Associate Provost Tim Jamison.

In a conversation prepared for MIT News, Provost Martin Schmidt described the plan’s importance to the Institute, the processes that will lead to its successful implementation, and MIT’s generational opportunity for change.

Q: What are the opportunities and challenges you face as provost in trying to advance a strategic plan for diversity, equity, and inclusion at MIT? 

A: We are living through a transformational time — from increasing political polarization; to the Covid-19 pandemic; to the deep changes we are seeing in how our society talks about race, gender, and other identity issues. In the past, some might have considered these issues as happening “outside” our campus. We know today all of these challenges, and others, are landing squarely inside the MIT community. Fundamentally, I want to make sure we recognize the moment we’re in and work to build a community that is greater than the sum of its parts.

The strategic action plan is MIT’s opportunity to define much of the work we need to do. It’s a platform for building a rich network that’s mutually supportive. It’s an opportunity to amplify and propagate good ideas and practices across the Institute. We need to make sure good ideas spread, and to share lessons learned about things that don’t work.

We all know MIT is decentralized. Sometimes collaboration doesn’t happen naturally. However, there is already a huge range of productive interdepartmental and interdisciplinary relationships on our campus, are they’re generating tremendous results. If we capture and redirect some of this energy and build a connected network of diversity, equity, and inclusion activities at MIT, it will elevate everything we do.

The strategic plan is also a pathway to building a network of accountability. Everyone — by which I mean every organizational unit at the Institute — needs a plan for its community. MIT has a range of distinct cultures and communities. What the strategic plan will give us is a unifying framework, a set of principles, and the tools to make sure that local-area planning is well thought out and fits together — that they, too, add up to a whole greater than the parts. And across this framework, of course, we’re going to measure and track the success of everything we do.

Finally, we need to be smart about resource allocation. MIT has already made crucial investments in diversity, equity, and inclusion, such as the hiring of six new assistant deans for diversity in the schools and the college. We need to build on those investments. We also need to be prepared to examine legacy programs and determine if they suit current needs and priorities. Tracking the effectiveness of the investments we’ve made is as important as making new ones.

Q: How do you think the plan will impact the campus community?

A: A more diverse and inclusive community leads to better outcomes, no matter how you measure them. It will also lead to a better and more impactful MIT. We want this plan to cultivate and promote an environment where everyone feels empowered to generate better ideas, to make more informed decisions, and to pursue the opportunities they are passionate about. This isn’t just for students, or faculty, or staff, or our postdocs — this plan is for every person who is a part of the MIT community.

This is why we need local planning. For the strategic plan to reach effectively across MIT functional areas — from staff professional development, to graduate student admissions, to faculty recruitment, to our work with external partners — it must be informed by and connected with the expertise in those areas. This level of detail and engagement makes the process complicated, but I can’t see an alternative, at least not one that will actually work and get us where we want to be.

Q: What do you think will be the most important outcome of the plan? 

A: I think there are internal and external dimensions to this.

Internally, I don’t think MIT has ever done something this unifying before. We need to develop some new capabilities and some new muscles around collaboration and coordination. The Provost’s Office is among the few places at MIT that is sufficiently central to help move the strategic plan forward. And we need partners — the chancellor, Human Resources, the vice president for research, and others — if we’re going to get everyone at MIT rowing in the same direction. Plus, those of us in more central roles need active and meaningful participation from the members of our communities in order to accomplish our goals.

The old saying that no organization ever centralized its way out of a problem applies here. Centralization is not our goal. We need to provide enough central support to make the pieces come together. I think that’s new and different for MIT.

Externally, I am always humbled and surprised by how much people pay attention to MIT. Our peer schools, especially STEM-oriented universities, often look to us as they reflect on what they’re doing. There are some widely acknowledged challenges when it comes to diversity in STEM fields. We have a generational opportunity to address these challenges. We might not be doing any better than our peers, but we are a place where people look to for cues and models. If we can help propel the community of STEM institutions — through collaboration and sharing of best practices — MIT can propel change beyond our campus.

Company founded by MIT alumnus lets anyone run DNA experiments

Tue, 08/17/2021 - 12:00am

If you gave students around the world the power to study and manipulate genes in a test tube, what would they do with it?

MiniPCR bio first began selling its portable, inexpensive polymerase chain reaction (PCR) machines in 2013. The machines allow users to multiply specific strands of DNA in minutes, following along with experiments through a phone app.

Since then, the founders have been amazed at the amount of learning and research that has come from the devices.

Researchers have taken the machines into the Amazon rainforest, the deep oceans, and onto remote islands to do things like classify the DNA of the Ebola virus, sequence genes in endangered animals, and monitor for disease. Hundreds of thousands of students have used the machines for hands-on classroom experiments. The machines have even gone to the International Space Station as part of miniPCR bio’s Genes in Space initiative.

The space experiments are designed by middle and high school students as one of miniPCR bio’s projects in education, its main focus. To date, miniPCR bio has sold more than 20,000 of its machines to schools in 80 countries across the globe.

“I still find it shocking,” miniPCR bio’s co-founder Ezequiel Alvarez Saavedra PhD ’08 says of the company’s impact. “We get emails from teachers every week thanking us and telling us how much learning improved in the classroom because of our machine. I never would have thought this would happen.”

Making PCR mainstream

Alvarez Saavedra conducted thousands of experiments with PCR machines, which help researchers replicate specific pieces of DNA and RNA, as part of his PhD work at MIT studying the C. elegans worm. After completing his PhD in 2008, he wasn’t sure how to continue his research career, but he’d worked at MIT’s Hobby Shop in his free time and knew he liked building things, so he began working with a small engineering firm to design a simpler machine.

“I wasn't thinking of starting a company at all,” Alvarez Saavedra says. “I just liked engineering and I was hoping to learn more about it.”

PCR machines work through a series of temperature changes. First, DNA is heated up inside the machine’s sample tubes. The heat breaks the DNA’s two strands apart. Then, during a cool down phase, molecules specifying the start and end point of the DNA that scientists want to replicate latch onto their targets. As the PCR machine heats the sample back up, an enzyme fills in the target section of DNA, matching the A nucleotides with Ts and the C nucleotides with Gs. The heat-cool-heat cycle is repeated over and over until millions of copies of the target section have been generated.

“PCR is really the workhorse of molecular biology,” Alvarez Saavedra says. “PCR lets you zoom into your region of interest — the starting material could be an entire genome or a small piece of DNA — and then do something with it. You can sequence it, for example, or you could remove a piece of it.”

Traditional PCR machines cost thousands of dollars and typically use thermoelectric cooling to change temperatures. MiniPCR’s machines, the most popular of which costs $650, use a fan and a thin-film heater, simplifying their design and making their operation far less energy-intensive.

Those changes make the machines cheap. They’re also far easier to use than their lab-based counterparts. A simple app lets users select what kind of experiment they want to run, and a temperature graph with animated depictions lets students and researchers follow along at every stage.

In 2013, Alvarez Saavedra partnered with Sebastian Kraves, a fellow Argentinian who’d earned his PhD at Harvard Medical School, to consider the best use case for the new invention. The co-founders decided to try expanding access to PCR machines for middle and high school students around the globe.

To show educators the machines for the first time, the founders attended a professional development training session for teachers at MIT.

“We showed it for 10 minutes and a teacher at the back of the room immediately said, ‘I want 10 of those,’” Alvarez Saavedra remembers. “We thought okay, there's something here.”

The founders ended up building the first 20 machines themselves, storing growing numbers of them in Ezequiel’s living room and basement until his wife suggested they find an office.

Fortunately, miniPCR bio was quickly gaining traction in the education space. Many schools buy batches of miniPCR machines for groups of students to work with directly.

“U.S. schools have been teaching PCR for years, but pretty much no one at the time had PCR machines,” Alvarez Saavedra says. “If a school did have a PCR machine, it would sit at the back of the classroom. When you're teaching you want small groups of students doing experiments that allows each one to be more hands-on.”

As miniPCR bio’s impact on education scaled, it also gained a loyal following among researchers who appreciate the device’s low price point, efficiency, and suitability to travel to remote regions.

Researchers have run the machines off batteries charged with solar panels and done experiments without leaving the field. When one researcher was trying to sequence the Ebola virus in a makeshift lab in Sierra Leone, the miniPCR machines he’d brought to train lab technicians proved more effective than the traditional — far more expensive — PCR machines he’d brought for his work.

“It’s very nice to get reminded what you're doing has an impact,” Alvarez Saavedra says.

PCR and beyond

Early on, the founders had the idea for students to design experiments for astronauts to run in space. The idea grew into a national competition held in partnership with Boeing that invites middle and high school students to propose pioneering DNA experiments that address challenges in space exploration. Finalist teams receive miniPCR machines for their schools, and winners get to see their experiments carried out in the International Space Station.

“Kids find space and molecular biology very exciting,” Alvarez Saavedra says.

MiniPCR has done eight missions so far. The program is just one example of the miniPCR team’s ability to keep innovating. The company also offers inexpensive systems for visualizing DNA and enzymes. It’s also developed projects for running classroom experiments using gene editing and synthetic biology. The latter project, called Biobits, was codeveloped in the lab of Jim Collins, the Termeer Professor of Medical Engineering and Science at MIT.

Biobits gives students a hands-on introduction to synthetic biology by letting them create molecular factories that churn out brightly colored proteins, functional enzymes, and more. Ally Huang, a grad student in Collins’ lab who helped develop Biobits, joined the miniPCR team to help launch the first Biobits labs and has helped scale the program to classrooms across the country.

“We try to go where the exciting science is,” Alvarez Saavedra says. “With all these programs, it’s been crazy. You put it out and you start hearing from people in all these crazy places. In the beginning, this wasn’t even supposed to be a company. But it’s incredibly simple. I guess that’s the beauty of it.”

“AI for Impact” lives up to its name

Mon, 08/16/2021 - 5:00pm

For entrepreneurial MIT students looking to put their skills to work for a greater good, the Media Arts and Sciences class MAS.664 (AI for Impact) has been a destination point. With the onset of the pandemic, that goal came into even sharper focus. Just weeks before the campus shut down in 2020, a team of students from the class launched a project that would make significant strides toward an open-source platform to identify coronavirus exposures without compromising personal privacy.

Their work was at the heart of Safe Paths, one of the earliest contact tracing apps in the United States. The students joined with volunteers from other universities, medical centers, and companies to publish their code, alongside a well-received white paper describing the privacy-preserving, decentralized protocol, all while working with organizations wishing to launch the app within their communities. The app and related software eventually got spun out into the nonprofit PathCheck Foundation, which today engages with public health entities and is providing exposure notifications in Guam, Cyprus, Hawaii, Minnesota, Alabama, and Louisiana.

The formation of Safe Paths demonstrates the special sense among MIT researchers that “we can launch something that can help people around the world,” notes Media Lab Associate Professor Ramesh Raskar, who teaches the class together with Media Lab Professor Alex “Sandy” Pentland and Media Lab Lecturer Joost Bonsen. “To have that kind of passion and ambition — but also the confidence that what you create here can actually be deployed globally — is kind of amazing.”

AI for Impact, created by Pentland, began meeting two decades ago under the course name Development Ventures, and has nurtured multiple thriving businesses. Examples of class ventures that Pentland incubated or co-founded include Dimagi, Cogito, Ginger, Prosperia, and Sanergy.

The aim-high challenge posed to each class is to come up with a business plan that touches a billion people, and it can’t all be in one country, Pentland explains. Not every class effort becomes a business, “but 20 percent to 30 percent of students start something, which is great for an entrepreneur class,” says Pentland.

Opportunities for Impact

The numbers behind Dimagi, for instance, are striking. Its core product CommCare has helped front-line health workers provide care for more than 400 million people in more than 130 countries around the world. When it comes to maternal and child care, Dimagi's platform has registered one in every 110 pregnancies worldwide. This past year, several governments around the world deployed CommCare applications for Covid-19 response — from Sierra Leone and Somalia to New York and Colorado.

Spinoffs like Cogito, Prosperia, and Ginger have likewise grown into highly successful companies. Cogito helps a million people a day gain access to the health care they need; Prosperia helps manage social support payments to 80 million people in Latin America; and Ginger handles mental health services for over 1 million people.

The passion behind these and other class ventures points to a central idea of the class, Pentland notes: MIT students are often looking for ways to build entrepreneurial businesses that enable positive social change.

During the spring 2021 class, for example, a number of promising student projects included tools to help residents of poor communities transition to owning their homes rather than renting, and to take better control of their community health.

“It’s clear that the people who are graduating from here want to do something significant with their lives ... they want to have an impact on their world,” Pentland says. "This class enables them to meet other people who are interested in doing the same thing, and offers them some help in starting a company to do it.”

Many of the students who join the class come in with a broad set of interests. Guest lectures, case studies of other social entrepreneurship projects, and an introduction to a broad ecosystem of expertise and funding, then helps students to refine their general ideas into specific and viable projects.

A path toward confronting a pandemic 

Raskar began co-teaching the class in 2019, and brought a “Big AI” focus to the Development Ventures class, inspired by an AI for Impact team he had set up at his former employer, Facebook. “What I realized is that companies like Google or Facebook or Amazon actually have enough data about all of us that they can solve major problems in our society — climate, transportation, health, and so on,” he says. “This is something we should think about more seriously: how to use AI and data for positive social impact, while protecting privacy.”

Early into the spring 2020 class, as students were beginning to consider their own projects, Raskar approached the class about the emerging coronavirus outbreak. Students like Kristen Vilcans recognized the urgency, and the opportunity. She and 10 other students joined forces to work on a project that would focus on Covid-19.

"Students felt empowered to do something to help tackle the spread of this alarming new virus," Raskar recalls. "They immediately began to develop data- and AI-based solutions to one of the most critical pieces of addressing a pandemic: halting the chain of infections. They created and launched one of the first digital contact tracing and exposure notification solutions in the U.S., developing an early alert system that engaged the public and protected privacy.” 

Raskar looks back on the moment when a core group of students coalesced into a team. “It was very rare for a significant part of the class to just come together saying, 'let’s do this, right away.' It became as much a movement as a venture.”

Group discussions soon began to center around an open-source, privacy-first digital set of tools for Covid-19 contact tracing. For the next two weeks, right up to the campus shutdown in March 2020, the team took over two adjacent conference rooms in the Media Lab, and started a Slack messaging channel devoted to the project. As the team members reached out to an ever-wider circle of friends, colleagues, and mentors, the number of participants grew to nearly 1,600 people, coming together virtually from all corners of the world.

Kaushal Jain, a Harvard Business School student who had cross-registered for the spring 2020 class to get to know the MIT ecosystem, was also an early participant in Safe Paths. He wrote up an initial plan for the venture and began working with external organizations to figure out how to structure it into a nonprofit company. Jain eventually became the project's lead for funding and partnerships.

Vilcans, a graduate student in system design and management, served as Safe Paths’ communications lead through July 2020, while still working a part-time job at Draper Laboratory and taking classes.

“There are these moments when you want to dive in, you want to contribute and you want to work nonstop,” she says, adding that the experience was also a wake-up call on how to manage burnout, and how to balance what you need as a person while contributing to a high-impact team. “That's important to understand as a leader for the future.”

MIT recognized Vilcan's contributions later that year with the 2020 SDM Student Award for Leadership, Innovation, and Systems Thinking. 

Jain, too, says the class gave him more than he could have expected.

“I made strong friendships with like-minded people from very different backgrounds,” he says. “One key thing that I learned was to be flexible about the kind of work you want to do. Be open and see if there's an opportunity, either through crisis or through something that you believe could really change a lot of things in the world. And then just go for it.”

Energy storage from a chemistry perspective

Mon, 08/16/2021 - 4:00pm

The transition toward a more sustainable, environmentally sound electrical grid has driven an upsurge in renewables like solar and wind. But something as simple as cloud cover can cause grid instability, and wind power is inherently unpredictable. This intermittent nature of renewables has invigorated the competitive landscape for energy storage companies looking to enhance power system flexibility while enabling the integration of renewables.

“Impact is what drives PolyJoule more than anything else,” says CEO Eli Paster. “We see impact from a renewable integration standpoint, from a curtailment standpoint, and also from the standpoint of transitioning from a centralized to a decentralized model of energy-power delivery.”

PolyJoule is a Billerica, Massachusetts-based startup that’s looking to reinvent energy storage from a chemistry perspective. Co-founders Ian Hunter of MIT's Department of Mechanical Engineering and Tim Swager of the Department of Chemistry are longstanding MIT professors considered luminaries in their respective fields. Meanwhile, the core team is a small but highly skilled collection of chemists, manufacturing specialists, supply chain optimizers, and entrepreneurs, many of whom have called MIT home at one point or another.

“The ideas that we work on in the lab, you’ll see turned into products three to four years from now, and they will still be innovative and well ahead of the curve when they get to market,” Paster says. “But the concepts come from the foresight of thinking five to 10 years in advance. That’s what we have in our back pocket, thanks to great minds like Ian and Tim.”

PolyJoule takes a systems-level approach married to high-throughput, analytical electrochemistry that has allowed the company to pinpoint a chemical cell design based on 10,000 trials. The result is a battery that is low-cost, safe, and has a long lifetime. It's capable of responding to base loads and peak loads in microseconds, allowing the same battery to participate in multiple power markets and deployment use cases.

In the energy storage sphere, interesting technologies abound, but workable solutions are few and far between. But Paster says PolyJoule has managed to bridge the gap between the lab and the real world by taking industry concerns into account from the beginning. “We’ve taken a slightly contrarian view to all of the other energy storage companies that have come before us that have said, ‘If we build it, they will come.’ Instead, we’ve gone directly to the customer and asked, ‘If you could have a better battery storage platform, what would it look like?’”

With commercial input feeding into the thought processes behind their technological and commercial deployment, PolyJoule says they've designed a battery that is less expensive to make, less expensive to operate, safer, and easier to deploy.

Traditionally, lithium-ion batteries have been the go-to energy storage solution. But lithium has its drawbacks, including cost, safety issues, and detrimental effects on the environment. But PolyJoule isn’t interested in lithium — or metals of any kind, in fact. "We start with the periodic table of organic elements,” says Paster, “and from there, we derive what works at economies of scale, what is easy to converge and convert chemically.”

Having an inherently safer chemistry allows PolyJoule to save on system integration costs, among other things. PolyJoule batteries don’t contain flammable solvents, which means no added expenses related to fire mitigation. Safer chemistry also means ease of storage, and PolyJoule batteries are currently undergoing global safety certification (UL approval) to be allowed indoors and on airplanes. Finally, with high power built into the chemistry, PolyJoule’s cells can be charged and discharged to extremes, without the need for heating or cooling systems.

“From raw material to product delivery, we examine each step in the value chain with an eye towards reducing costs,” says Paster. It all starts with designing the chemistry around earth-abundant elements, which allows the small startup to compete with larger suppliers, even at smaller scales. Consider the fact that PolyJoule’s differentiating material cost is less than $1 per kilogram, whereas lithium carbonate sells for $20 per kilogram.

On the manufacturing side, Paster explains that PolyJoule cuts costs by making their cells in old paper mills and warehouses, employing off-the-shelf equipment previously used for tissue paper or newspaper printing. "We use equipment that has been around for decades because we don't want to create a cutting-edge technology that requires cutting-edge manufacturing," he says. "We want to create a cutting-edge technology that can be deployed in industrialized nations and in other nations that can benefit the most from energy storage."

PolyJoule’s first customer is an industrial distributed energy consumer with baseline energy consumption that increases by a factor of 10 when the heavy machinery kicks on twice a day. In the early morning and late afternoon, it consumes about 50 kilowatts for 20 minutes to an hour, compared to a baseline rate of 5  kilowatts. It’s an application model that is translatable to a variety of industries. Think wastewater treatment, food processing, and server farms — anything with a fluctuation in power consumption over a 24-hour period.

By the end of the year, PolyJoule will have delivered its first 10 kilowatt-hour system, exiting stealth mode and adding commercial viability to demonstrated technological superiority. "What we're seeing, now is massive amounts of energy storage being added to renewables and grid-edge applications," says Paster. "We anticipated that by 12-18 months, and now we're ramping up to catch up with some of the bigger players.”

Designing better batteries for electric vehicles

Mon, 08/16/2021 - 3:30pm

The urgent need to cut carbon emissions is prompting a rapid move toward electrified mobility and expanded deployment of solar and wind on the electric grid. If those trends escalate as expected, the need for better methods of storing electrical energy will intensify.

“We need all the strategies we can get to address the threat of climate change,” says Elsa Olivetti PhD ’07, the Esther and Harold E. Edgerton Associate Professor in Materials Science and Engineering. “Obviously, developing technologies for grid-based storage at a large scale is critical. But for mobile applications — in particular, transportation — much research is focusing on adapting today’s lithium-ion battery to make versions that are safer, smaller, and can store more energy for their size and weight.”

Traditional lithium-ion batteries continue to improve, but they have limitations that persist, in part because of their structure. A lithium-ion battery consists of two electrodes — one positive and one negative — sandwiched around an organic (carbon-containing) liquid. As the battery is charged and discharged, electrically charged particles (or ions) of lithium pass from one electrode to the other through the liquid electrolyte.

One problem with that design is that at certain voltages and temperatures, the liquid electrolyte can become volatile and catch fire. “Batteries are generally safe under normal usage, but the risk is still there,” says Kevin Huang PhD ’15, a research scientist in Olivetti’s group.

Another problem is that lithium-ion batteries are not well-suited for use in vehicles. Large, heavy battery packs take up space and increase a vehicle’s overall weight, reducing fuel efficiency. But it’s proving difficult to make today’s lithium-ion batteries smaller and lighter while maintaining their energy density — that is, the amount of energy they store per gram of weight.

To solve those problems, researchers are changing key features of the lithium-ion battery to make an all-solid, or “solid-state,” version. They replace the liquid electrolyte in the middle with a thin, solid electrolyte that’s stable at a wide range of voltages and temperatures. With that solid electrolyte, they use a high-capacity positive electrode and a high-capacity, lithium metal negative electrode that’s far thinner than the usual layer of porous carbon. Those changes make it possible to shrink the overall battery considerably while maintaining its energy-storage capacity, thereby achieving a higher energy density.

“Those features — enhanced safety and greater energy density — are probably the two most-often-touted advantages of a potential solid-state battery,” says Huang. He then quickly clarifies that “all of these things are prospective, hoped-for, and not necessarily realized.” Nevertheless, the possibility has many researchers scrambling to find materials and designs that can deliver on that promise.

Thinking beyond the lab

Researchers have come up with many intriguing options that look promising — in the lab. But Olivetti and Huang believe that additional practical considerations may be important, given the urgency of the climate change challenge. “There are always metrics that we researchers use in the lab to evaluate possible materials and processes,” says Olivetti. Examples might include energy-storage capacity and charge/discharge rate. When performing basic research — which she deems both necessary and important — those metrics are appropriate. “But if the aim is implementation, we suggest adding a few metrics that specifically address the potential for rapid scaling,” she says.

Based on industry’s experience with current lithium-ion batteries, the MIT researchers and their colleague Gerbrand Ceder, the Daniel M. Tellep Distinguished Professor of Engineering at the University of California at Berkeley, suggest three broad questions that can help identify potential constraints on future scale-up as a result of materials selection. First, with this battery design, could materials availability, supply chains, or price volatility become a problem as production scales up? (Note that the environmental and other concerns raised by expanded mining are outside the scope of this study.) Second, will fabricating batteries from these materials involve difficult manufacturing steps during which parts are likely to fail? And third, do manufacturing measures needed to ensure a high-performance product based on these materials ultimately lower or raise the cost of the batteries produced?

To demonstrate their approach, Olivetti, Ceder, and Huang examined some of the electrolyte chemistries and battery structures now being investigated by researchers. To select their examples, they turned to previous work in which they and their collaborators used text- and data-mining techniques to gather information on materials and processing details reported in the literature. From that database, they selected a few frequently reported options that represent a range of possibilities.

Materials and availability

In the world of solid inorganic electrolytes, there are two main classes of materials — the oxides, which contain oxygen, and the sulfides, which contain sulfur. Olivetti, Ceder, and Huang focused on one promising electrolyte option in each class and examined key elements of concern for each of them.

The sulfide they considered was LGPS, which combines lithium, germanium, phosphorus, and sulfur. Based on availability considerations, they focused on the germanium, an element that raises concerns in part because it’s not generally mined on its own. Instead, it’s a byproduct produced during the mining of coal and zinc.

To investigate its availability, the researchers looked at how much germanium was produced annually in the past six decades during coal and zinc mining and then at how much could have been produced. The outcome suggested that 100 times more germanium could have been produced, even in recent years. Given that supply potential, the availability of germanium is not likely to constrain the scale-up of a solid-state battery based on an LGPS electrolyte.

The situation looked less promising with the researchers’ selected oxide, LLZO, which consists of lithium, lanthanum, zirconium, and oxygen. Extraction and processing of lanthanum are largely concentrated in China, and there’s limited data available, so the researchers didn’t try to analyze its availability. The other three elements are abundantly available. However, in practice, a small quantity of another element — called a dopant — must be added to make LLZO easy to process. So the team focused on tantalum, the most frequently used dopant, as the main element of concern for LLZO.

Tantalum is produced as a byproduct of tin and niobium mining. Historical data show that the amount of tantalum produced during tin and niobium mining was much closer to the potential maximum than was the case with germanium. So the availability of tantalum is more of a concern for the possible scale-up of an LLZO-based battery.

But knowing the availability of an element in the ground doesn’t address the steps required to get it to a manufacturer. So the researchers investigated a follow-on question concerning the supply chains for critical elements — mining, processing, refining, shipping, and so on. Assuming that abundant supplies are available, can the supply chains that deliver those materials expand quickly enough to meet the growing demand for batteries?

In sample analyses, they looked at how much supply chains for germanium and tantalum would need to grow year to year to provide batteries for a projected fleet of electric vehicles in 2030. As an example, an electric vehicle fleet often cited as a goal for 2030 would require production of enough batteries to deliver a total of 100 gigawatt hours of energy. To meet that goal using just LGPS batteries, the supply chain for germanium would need to grow by 50 percent from year to year — a stretch, since the maximum growth rate in the past has been about 7 percent. Using just LLZO batteries, the supply chain for tantalum would need to grow by about 30 percent — a growth rate well above the historical high of about 10 percent.

Those examples demonstrate the importance of considering both materials availability and supply chains when evaluating different solid electrolytes for their scale-up potential. “Even when the quantity of a material available isn’t a concern, as is the case with germanium, scaling all the steps in the supply chain to match the future production of electric vehicles may require a growth rate that’s literally unprecedented,” says Huang.

Materials and processing

In assessing the potential for scale-up of a battery design, another factor to consider is the difficulty of the manufacturing process and how it may impact cost. Fabricating a solid-state battery inevitably involves many steps, and a failure at any step raises the cost of each battery successfully produced. As Huang explains, “You’re not shipping those failed batteries; you’re throwing them away. But you’ve still spent money on the materials and time and processing.”

As a proxy for manufacturing difficulty, Olivetti, Ceder, and Huang explored the impact of failure rate on overall cost for selected solid-state battery designs in their database. In one example, they focused on the oxide LLZO. LLZO is extremely brittle, and at the high temperatures involved in manufacturing, a large sheet that’s thin enough to use in a high-performance solid-state battery is likely to crack or warp.

To determine the impact of such failures on cost, they modeled four key processing steps in assembling LLZO-based batteries. At each step, they calculated cost based on an assumed yield — that is, the fraction of total units that were successfully processed without failing. With the LLZO, the yield was far lower than with the other designs they examined; and, as the yield went down, the cost of each kilowatt-hour (kWh) of battery energy went up significantly. For example, when 5 percent more units failed during the final cathode heating step, cost increased by about $30/kWh — a nontrivial change considering that a commonly accepted target cost for such batteries is $100/kWh. Clearly, manufacturing difficulties can have a profound impact on the viability of a design for large-scale adoption.

Materials and performance

One of the main challenges in designing an all-solid battery comes from “interfaces” — that is, where one component meets another. During manufacturing or operation, materials at those interfaces can become unstable. “Atoms start going places that they shouldn’t, and battery performance declines,” says Huang.

As a result, much research is devoted to coming up with methods of stabilizing interfaces in different battery designs. Many of the methods proposed do increase performance; and as a result, the cost of the battery in dollars per kWh goes down. But implementing such solutions generally involves added materials and time, increasing the cost per kWh during large-scale manufacturing.

To illustrate that trade-off, the researchers first examined their oxide, LLZO. Here, the goal is to stabilize the interface between the LLZO electrolyte and the negative electrode by inserting a thin layer of tin between the two. They analyzed the impacts — both positive and negative — on cost of implementing that solution. They found that adding the tin separator increases energy-storage capacity and improves performance, which reduces the unit cost in dollars/kWh. But the cost of including the tin layer exceeds the savings so that the final cost is higher than the original cost.

In another analysis, they looked at a sulfide electrolyte called LPSCl, which consists of lithium, phosphorus, and sulfur with a bit of added chlorine. In this case, the positive electrode incorporates particles of the electrolyte material — a method of ensuring that the lithium ions can find a pathway through the electrolyte to the other electrode. However, the added electrolyte particles are not compatible with other particles in the positive electrode — another interface problem. In this case, a standard solution is to add a “binder,” another material that makes the particles stick together.

Their analysis confirmed that without the binder, performance is poor, and the cost of the LPSCl-based battery is more than $500/kWh. Adding the binder improves performance significantly, and the cost drops by almost $300/kWh. In this case, the cost of adding the binder during manufacturing is so low that essentially all the of the cost decrease from adding the binder is realized. Here, the method implemented to solve the interface problem pays off in lower costs.

The researchers performed similar studies of other promising solid-state batteries reported in the literature, and their results were consistent: The choice of battery materials and processes can affect not only near-term outcomes in the lab but also the feasibility and cost of manufacturing the proposed solid-state battery at the scale needed to meet future demand. The results also showed that considering all three factors together — availability, processing needs, and battery performance — is important because there may be collective effects and trade-offs involved.

Olivetti is proud of the range of concerns the team’s approach can probe. But she stresses that it’s not meant to replace traditional metrics used to guide materials and processing choices in the lab. “Instead, it’s meant to complement those metrics by also looking broadly at the sorts of things that could get in the way of scaling” — an important consideration given what Huang calls “the urgent ticking clock” of clean energy and climate change.

This research was supported by the Seed Fund Program of the MIT Energy Initiative (MITEI) Low-Carbon Energy Center for Energy Storage; by Shell, a founding member of MITEI; and by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, under the Advanced Battery Materials Research Program. The text mining work was supported by the National Science Foundation, the Office of Naval Research, and MITEI.

This article appears in the Spring 2021 issue of Energy Futures, the magazine of the MIT Energy Initiative.

Jacqueline Lees and Rebecca Saxe named associate deans of science

Mon, 08/16/2021 - 3:00pm

Jaqueline Lees and Rebecca Saxe have been named associate deans serving in the MIT School of Science. Lees is the Virginia and D.K. Ludwig Professor for Cancer Research and is currently the associate director of the Koch Institute for Integrative Cancer Research, as well as an associate department head and professor in the Department of Biology at MIT. Saxe is the John W. Jarve (1978) Professor in Brain and Cognitive Sciences and the associate head of the Department of Brain and Cognitive Sciences (BCS); she is also an associate investigator in the McGovern Institute for Brain Research.

Lees and Saxe will both contribute to the school’s diversity, equity, inclusion, and justice (DEIJ) activities, as well as develop and implement mentoring and other career-development programs to support the community. From their home departments, Saxe and Lees bring years of DEIJ and mentorship experience to bear on the expansion of school-level initiatives.

Lees currently serves on the dean’s science council in her capacity as associate director of the Koch Institute. In this new role as associate dean for the School of Science, she will bring her broad administrative and programmatic experiences to bear on the next phase for DEIJ and mentoring activities.

Lees joined MIT in 1994 as a faculty member in MIT’s Koch Institute (then the Center for Cancer Research) and Department of Biology. Her research focuses on regulators that control cellular proliferation, terminal differentiation, and stemness — functions that are frequently deregulated in tumor cells. She dissects the role of these proteins in normal cell biology and development, and establish how their deregulation contributes to tumor development and metastasis.

Since 2000, she has served on the Department of Biology’s graduate program committee, and played a major role in expanding the diversity of the graduate student population. Lees also serves on DEIJ committees in her home department, as well as at the Koch Institute.

With co-chair with Boleslaw Wyslouch, director of the Laboratory for Nuclear Science, Lees led the ReseArch Scientist CAreer LadderS (RASCALS) committee tasked to evaluate career trajectories for research staff in the School of Science and make recommendations to recruit and retain talented staff, rewarding them for their contributions to the school’s research enterprise.

“Jackie is a powerhouse in translational research, demonstrating how fundamental work at the lab bench is critical for making progress at the patient bedside,” says Nergis Mavalvala, dean of the School of Science. “With Jackie’s dedicated and thoughtful partnership, we can continue to lead in basic research and develop the recruitment, retention, and mentoring and necessary to support our community.”

Saxe will join Lees in supporting and developing programming across the school that could also provide direction more broadly at the Institute.

“Rebecca is an outstanding researcher in social cognition and a dedicated educator — someone who wants our students not only to learn, but to thrive,” says Mavalvala. “I am grateful that Rebecca will join the dean’s leadership team and bring her mentorship and leadership skills to enhance the school.”  

For example, in collaboration with former department head James DiCarlo, the BCS department has focused on faculty mentorship of graduate students; and, in collaboration with Professor Mark Bear, the department developed postdoc salary and benefit standards. Both initiatives have become models at MIT.

With colleague Laura Schulz, Saxe also served as co-chair of the Committee on Medical Leave and Hospitalizations (CMLH), which outlined ways to enhance MIT’s current leave and hospitalization procedures and policies for undergraduate and graduate students. Saxe was also awarded MIT’s Committed to Caring award for excellence in graduate student mentorship, as well as the School of Science’s award for excellence in undergraduate teaching.

In her research, Saxe studies human social cognition, using a combination of behavioral testing and brain imaging technologies. She is best known for her work on brain regions specialized for abstract concepts, such as “theory of mind” tasks that involve understanding the mental states of other people. Her TED Talk, “How we read each other’s minds” has been viewed more than 3 million times. She also studies the development of the human brain during early infancy.

She obtained her PhD from MIT and was a Harvard University junior fellow before joining the MIT faculty in 2006. In 2014, the National Academy of Sciences named her one of two recipients of the Troland Award for investigators age 40 or younger “to recognize unusual achievement and further empirical research in psychology regarding the relationships of consciousness and the physical world.” In 2020, Saxe was named a John Simon Guggenheim Foundation Fellow.

Saxe and Lees will also work closely with Kuheli Dutt, newly hired assistant dean for diversity, equity, and inclusion, and other members of the dean’s science council on school-level initiatives and strategy.  

“I’m so grateful that Rebecca and Jackie have agreed to take on these new roles,” Mavalvala says. “And I’m super excited to work with these outstanding thought partners as we tackle the many puzzles that I come across as dean.”

Inflatable robotic hand gives amputees real-time tactile control

Mon, 08/16/2021 - 11:00am

For the more than 5 million people in the world who have undergone an upper-limb amputation, prosthetics have come a long way. Beyond traditional mannequin-like appendages, there is a growing number of commercial neuroprosthetics — highly articulated bionic limbs, engineered to sense a user’s residual muscle signals and robotically mimic their intended motions.

But this high-tech dexterity comes at a price. Neuroprosthetics can cost tens of thousands of dollars and are built around metal skeletons, with electrical motors that can be heavy and rigid.

Now engineers at MIT and Shanghai Jiao Tong University have designed a soft, lightweight, and potentially low-cost neuroprosthetic hand. Amputees who tested the artificial limb performed daily activities, such as zipping a suitcase, pouring a carton of juice, and petting a cat, just as well as — and in some cases better than —those with more rigid neuroprosthetics.

The researchers found the prosthetic, designed with a system for tactile feedback, restored some primitive sensation in a volunteer’s residual limb. The new design is also surprisingly durable, quickly recovering after being struck with a hammer or run over with a car.

The smart hand is soft and elastic, and weighs about half a pound. Its components total around $500 — a fraction of the weight and material cost associated with more rigid smart limbs.

“This is not a product yet, but the performance is already similar or superior to existing neuroprosthetics, which we’re excited about,” says Xuanhe Zhao, professor of mechanical engineering and of civil and environmental engineering at MIT. “There’s huge potential to make this soft prosthetic very low cost, for low-income families who have suffered from amputation.”

Zhao and his colleagues have published their work today in Nature Biomedical Engineering. Co-authors include MIT postdoc Shaoting Lin, along with Guoying Gu, Xiangyang Zhu, and collaborators at Shanghai Jiao Tong University in China.

Big Hero hand

The team’s pliable new design bears an uncanny resemblance to a certain inflatable robot in the animated film “Big Hero 6.” Like the squishy android, the team’s artificial hand is made from soft, stretchy material — in this case, the commercial elastomer EcoFlex. The prosthetic comprises five balloon-like fingers, each embedded with segments of fiber, similar to articulated bones in actual fingers. The bendy digits are connected to a 3-D-printed “palm,” shaped like a human hand.

Rather than controlling each finger using mounted electrical motors, as most neuroprosthetics do, the researchers used a simple pneumatic system to precisely inflate fingers and bend them in specific positions. This system, including a small pump and valves, can be worn at the waist, significantly reducing the prosthetic’s weight.

Lin developed a computer model to relate a finger’s desired position to the corresponding pressure a pump would have to apply to achieve that position. Using this model, the team developed a controller that directs the pneumatic system to inflate the fingers, in positions that mimic five common grasps, including pinching two and three fingers together, making a balled-up fist, and cupping the palm.

The pneumatic system receives signals from EMG sensors — electromyography sensors that measure electrical signals generated by motor neurons to control muscles. The sensors are fitted at the prosthetic’s opening, where it attaches to a user’s limb. In this arrangement, the sensors can pick up signals from a residual limb, such as when an amputee imagines making a fist.

The team then used an existing algorithm that “decodes” muscle signals and relates them to common grasp types. They used this algorithm to program the controller for their pneumatic system. When an amputee imagines, for instance, holding a wine glass, the sensors pick up the residual muscle signals, which the controller then translates into corresponding pressures. The pump then applies those pressures to inflate each finger and produce the amputee’s intended grasp.

Going a step further in their design, the researchers looked to enable tactile feedback — a feature that is not incorporated in most commercial neuroprosthetics. To do this, they stitched to each fingertip a pressure sensor, which when touched or squeezed produces an electrical signal proportional to the sensed pressure. Each sensor is wired to a specific location on an amputee’s residual limb, so the user can “feel” when the prosthetic’s thumb is pressed, for example, versus the forefinger.

Good grip

To test the inflatable hand, the researchers enlisted two volunteers, each with upper-limb amputations. Once outfitted with the neuroprosthetic, the volunteers learned to use it by repeatedly contracting the muscles in their arm while imagining making five common grasps.

After completing this 15-minute training, the volunteers were asked to perform a number of standardized tests to demonstrate manual strength and dexterity. These tasks included stacking checkers, turning pages, writing with a pen, lifting heavy balls, and picking up fragile objects like strawberries and bread. They repeated the same tests using a more rigid, commercially available bionic hand and found that the inflatable prosthetic was as good, or even better, at most tasks, compared to its rigid counterpart.

One volunteer was also able to intuitively use the soft prosthetic in daily activities, for instance to eat food like crackers, cake, and apples, and to handle objects and tools, such as laptops, bottles, hammers, and pliers. This volunteer could also safely manipulate the squishy prosthetic, for instance to shake someone’s hand, touch a flower, and pet a cat.

In a particularly exciting exercise, the researchers blindfolded the volunteer and found he could discern which prosthetic finger they poked and brushed. He was also able to “feel” bottles of different sizes that were placed in the prosthetic hand, and lifted them in response. The team sees these experiments as a promising sign that amputees can regain a form of sensation and real-time control with the inflatable hand.

The team has filed a patent on the design, through MIT, and is working to improve its sensing and range of motion.

“We now have four grasp types. There can be more,” Zhao says. “This design can be improved, with better decoding technology, higher-density myoelectric arrays, and a more compact pump that could be worn on the wrist. We also want to customize the design for mass production, so we can translate soft robotic technology to benefit society.”

Searching for multiplicity, in computer science and daily life

Sun, 08/15/2021 - 12:00am

Right now, Rodrigo Ochigame is reading Russian science fiction, Yugoslav art history, Indian philosophy, and Afro-Caribbean political theory. They are listening to Belgian electroacoustic music, Mongolian experimental rock, and Ethiopian jazz. Occasionally, the PhD student in the Program in History, Anthropology, and Science, Technology, and Society (HASTS) even throws dice to select a new MBTA stop to explore. More often, they apply this practice on the MIT campus, randomly attending departmental seminars on topics ranging from astrophysics to macroeconomics to neurobiology.

Ochigame’s freewheeling curiosity actually stems from a deep conviction about disrupting cultural assumptions — especially their own. “That’s something I’m trying to do with myself in everyday life. Whether it’s about reading literature or walking around new neighborhoods or attending research seminars in different disciplines, it’s a practice of intentionally unsettling yourself, of continually exposing yourself to divergent perspectives, so the ideas that are most familiar to you are disrupted,” they say.

In fact, Ochigame discovers many of the literary and musical works they are interested in through alternative search engines that they designed. For example, Search Atlas, a platform Ochigame developed in collaboration with computer scientist Katherine Ye, broadens a user’s search terms into a worldwide search for content. In so doing, the site reveals the geopolitical information boundaries embedded in conventional search engines like Google — boundaries that are invisible to most.

“Searching for multiplicity, for a plurality of intellectual traditions and for possibly marginalized perspectives, is the key principle behind the alternative search engines that I design. I want to expose people to ideas they wouldn’t find otherwise.” That principle permeates all aspects of Ochigame’s life.

Artificial separation

Ochigame grew up in a family of Japanese immigrants in Mato Grosso do Sul, Brazil, a region close to Bolivia, Paraguay, and the Pantanal tropical wetland. They describe Mato Grosso as a highly “syncretic” environment, where many different cultures, languages, and beliefs interweave.

“It’s really a place of cultural and linguistic syncretism. My own family had a mix of Buddhism, Christianity, and atheism. And in the border region, you also grow up amid many other influences, not only Portuguese and Spanish but also Lebanese, Okinawan, Guarani, Kaiowá, Terena, Afro-Brazilian. From an early age, I suppose, I’ve always been very puzzled by the diversity of available ways of understanding the world.”

Just as the seeds of their epistemological bent were sown in their hometown, Ochigame’s blossoming interest in computer science took root on the streets of Mato Grosso. One day while out walking, at age 13, Ochigame happened upon some other kids playing with an educational robotics kit. Captivated by the activity, which was expensive and unavailable at school, Ochigame began to learn about programming and engineering on the internet, largely through free video lectures from MIT OpenCourseWare. They built robots from cheaper microcontrollers, sensors, and actuators, ultimately gaining national recognition in Brazilian robotics competitions. By college, Ochigame was committed to studying computer science.

But soon after arriving at the University of California at Berkeley, more philosophical questions began to sprout in Ochigame’s mind. They enrolled in courses in the humanities and social sciences, and came to question the dominance of Western epistemological frameworks in computer science. The classes inspired them to unmask the implicit assumptions embedded in the supposedly “universal” formal models that computer scientists rely on.

“Algorithms encode the cultural assumptions of their designers,” Ochigame explains. “Computer scientists tend to think of their formal models as universal, but I see those models as products of particular cultural assumptions, economic conditions, and historical contingencies. Because of a false impression of universality, the orthodox models are rarely questioned.”

Such dogmatism, according to Ochigame, marginalizes important ideas. For example, their historical research uncovered that after the Cuban Revolution in 1959, Cuban information scientists developed library systems that sought to give visibility to marginalized points of view — a principle Ochigame now employs in their alternative search engines.

A broader view

When they considered graduate school, Ochigame sought a hybrid space where they could train in the humanities and think about computing from this different lens. The HASTS program at MIT has been a perfect fit. Under the guidance of Stefan Helmreich, the Elting E. Morison Professor of Anthropology, Ochigame’s graduate work has incorporated reading hundreds of books in anthropology, history, philosophy, and computer science, as well as traveling around the world to visit archives and conduct interviews with mathematicians, scientists, and engineers. The flexibility of the curriculum has allowed their ideas to mushroom.

“Even the most universalistic formal models of computation, like mathematical logic or Turing machines, encode particular cultural assumptions. I’m interested in how researchers from around the world have developed unorthodox models based on different assumptions. For example: nonclassical systems of logic from Brazil, nonbinary Turing machines from India, nonlinear electronic circuits from Japan, socialist frameworks of information science from Cuba. All over the world, people have imagined radically different ways of computing,” Ochigame says.

Beyond their research, Ochigame has found space at MIT to disrupt “universal” truths. As a teaching assistant for the popular course 21A.157 (The Meaning of Life), Ochigame led students in questioning cultural assumptions around topics like family, sex, and money. They also contributed to 6.036 (Introduction to Machine Learning), for which they co-designed the curriculum around ethical and social issues in computing and artificial intelligence.

“On the intellectual side of things, I couldn’t have asked for a better place than MIT,” Ochigame says. “It is, in fact, the only place I’ve ever felt a certain sense of belonging. The HASTS program is both supportive and transformative. My advisor is a model teacher who has incessantly disrupted my assumptions. I’ve had a wonderful time.” They add, “But, politically, I’m critical of the Institute. Going around multiple departments, I’ve become intimately aware of how funders shape research agendas. I’m worried by the Institute’s dependence on military and corporate sponsorship, because this dependence restricts the questions we ask.” For Ochigame, keeping a broad perspective should be not only a personal endeavor, but also a community and institutional one.

Reflecting that perspective, Ochigame’s living situation — cooperative housing in Cambridge, Massachusetts — comprises a multigenerational community of cultural and professional diversity. They enjoy the variety of guests that pass through, from street musicians to traveling monks, and can often be found chatting in the common areas and learning about those around them. Despite this plurality, the community is also one of shared values. “As a co-op, we make decisions democratically. We don’t have landlords. We strive to be a meeting place for diverse political struggles: prison abolition, queer and trans liberation, immigrant rights, and more,” they say.

Ochigame sees vast landscapes of perspectives where some may see neat gardens. But how does one see the forest through the trees?

“How do you make sense of multiplicity? It’s tempting to say that a single model of the world is the correct, rational, or scientifically valid one, while the others are not,” they say. “But another approach is to just take a step back and appreciate the variety of possible ways of making sense of the world out there.”

Katie Galloway receives NIH award to develop foundational tools for cellular engineering

Fri, 08/13/2021 - 3:25pm

Katie Galloway, the Charles and Hilda Roddey Career Development Assistant Professor of Chemical Engineering at MIT, has received a highly prestigious Maximizing Investigators’ Research Award (MIRA) from the National Institute of General Medical Sciences, part of the National Institutes of Health (NIH). The award, which grants $1.94 million over five years, will support Galloway’s work to develop multiscale tools and approaches for understanding and engineering cell-fate transitions.

Harnessing these design rules will enable the forward design of sophisticated genetic programs capable of robustly regulating gene expression in primary cells to support gene- and cell-based therapies for application in regenerative medicine.

“Our work aims to understand the molecular processes that support cell-fate transitions such as occur in development, reprogramming, and cancer,” says Galloway. “Using novel reporter circuits, we are identifying the processes that support the rare events that drive this cell-fate transition. By understanding how cells change fate, we aim to develop the next generation of synthetic gene circuits for tissue regeneration and repair.”

As a chemical engineer working in molecular systems biology, Galloway’s research focuses on elucidating the fundamental principles of integrating synthetic circuitry to drive cellular behaviors. Her lab works on developing integrated gene circuits and elucidating the systems-level principles that govern complex cellular behaviors.

Galloway’s team leverages synthetic biology to transform how we understand cellular transitions and engineer cellular therapies. Her research has been featured in Science, Cell Stem Cell, Cell Systems, and Development. Along with the recent MIRA, she has won multiple fellowships and awards including the NIH F32, and Caltech’s Everhart Award. Galloway studied chemical engineering at the University of California at Berkeley and obtained her PhD in chemical engineering at Caltech. She was a postdoc at USC Stem Cell within the University of Southern California before starting at MIT as an assistant professor in the summer of 2019.

The MIRA program supports investigators’ overall research programs through a single, unified grant rather than individual project grants. The goal is to provide investigators with greater stability and flexibility, thereby enhancing scientific productivity and the chances for important breakthroughs. The National Institute of General Medical Sciences supports basic research that increases our understanding of biological processes and lays the foundation for advances in disease diagnosis, treatment and prevention.

Professor Emeritus Lawrence Frishkopf, expert in communications biophysics, dies at 90

Fri, 08/13/2021 - 12:00pm

Lawrence Frishkopf, MIT professor emeritus of electrical engineering and computer science, died on June 25, one day before his 91st birthday.

An area chair in the department, Frishkopf was affiliated with both the Communications Biophysics group in the Research Laboratory of Electronics and the Harvard-MIT Program in Health Sciences and Technology, where his research focused on the biophysics of auditory systems.

Born in Philadelphia in 1930, he developed an interest in science as a young child, telling his Polish immigrant parents that he wanted to be an inventor when he grew up. He enjoyed carefree summers in Wildwood, New Jersey, while earning top grades in school, graduating as valedictorian from Olney High School in 1947, with a speech warning of the dangers of nuclear energy. He received a full scholarship to the University of Pennsylvania, where he majored in physics, gravitating towards theory, and graduating with a BS in 1951. That same year, he enrolled in graduate school at MIT with the intention of studying theoretical physics with Victor Weisskopf. An emerging interest in biophysics led Weisskopf to introduce him to Walter Rosenblith, who took Frishkopf on as his first graduate student and helped him to focus his work on sensory and motor systems. He completed the PhD in 1956, with a dissertation entitled "A probability approach to certain neuroelectric phenomena".

Many years later Frishkopf recalled that his graduate student days at MIT — a period during which he made lasting friendships and broadened his horizons to include new interests in literature, classical music, art, and sports — were among the best of his life. He took up squash at MIT's recreation center, and his friend and graduate student colleague and future Intel co-founder Robert Noyce taught him to ski the old fashioned way, hiking up Mt Washington's Tuckerman's Ravine.

He then completed a two-year postdoc working with physiologist and future Nobel Prize winner H. Keffer Hartline at the then-Rockefeller Institute for Medical Research. This was followed by a nine-year stint at Bell Laboratories, where, in 1964, Frishkopf received a patent for one of the first automatic handwriting recognition algorithms.

Frishkopf returned to MIT as a professor in 1968, and remained at the Institute until his retirement in 1996, developing a reputation as a leading authority on auditory biophysics in a variety of animal species, including cats, frogs, and bats, as well as people. Additionally, he conducted auditory research upon fish and skates, both of which use a lateral line organ, rather than the more familiar ear structure used by humans and other mammals. His MIT graduate students greatly appreciated his conscientious mentorship and care.

A lifelong lover of science and nature, he was an avid outdoorsman who relished introducing his children, stepchildren, and grandchildren to the natural world through nature walks, hiking, skiing, and trips to the seashore. A frequent bicycle commuter who rode from his home in Lexington, Massachusetts, to MIT, he was also a passionate runner until his mid-80s. Later he enjoyed his daily strolls around Fresh Pond in Cambridge with his beloved Sheltie, Heschy. A true Renaissance man, Frishkopf also took retirement as the opportunity to delve into wide-ranging interests, including drawing, music, sculpture, acting, Yiddish literature, and Buddhist meditation.

Frishkopf is remembered by his loving family, as well as the MIT community, as a gentle, thoughtful, caring man, with a remarkable capacity for deep compassion, and a wonderful sense of humor. He is survived by his wife, Janice Frishkopf; children Sophie, John, and Michael Frishkopf; stepchildren Ariel and Zachary Cahn; and seven grandchildren. He was predeceased by his ex-wife and friend, Barbara Frishkopf. Contributions may be made in his name to Doctors without Borders.

Study provides suggestions for keeping classroom air fresh

Fri, 08/13/2021 - 12:00am

Open windows and a good heating, ventilation, and air conditioning (HVAC) system are starting points for keeping classrooms safe during the Covid-19 pandemic. But they are not the last word, according to a new study from researchers at MIT.

The study shows how specific classroom configurations may affect air quality and necessitate additional measures, beyond HVAC use or open windows, to reduce the spread of aerosols — those tiny, potentially Covid-carrying particles that can stay suspended in the air for hours.

“There are sets of conditions where we found clearly there’s a problem, and when you look at the predicted concentration of aerosols around other people in the room, in some cases it was much higher than what the [standard] models would say,” says Leon Glicksman, an MIT architecture and engineering professor who is co-author of a new paper detailing the research.

Indeed, the study shows that some circumstances can create a concentration of potentially problematic aerosols ranging from 50 to 150 percent higher than the standard baseline concentration that experts regard as “well-mixed” indoors air.

“It gets complicated, and it depends on the particular conditions of the room,” Glicksman adds.

The paper, “Patterns of SARS-CoV-2 aerosol spread in typical classrooms,” appears in advance online form in the journal Building and Environment. The authors are Gerhard K. Rencken and Emma K. Rutherford, MIT undergraduates who participated in the research through the Undergraduate Research Opportunities Program with support from the MIT Energy Initiative; Nikhilesh Ghanta, a graduate student at MIT’s Center for Computational Science and Engineering; John Kongoletos, a graduate student in the Building Technology Program at MIT and a fellow at MIT’s Tata Center; and Glicksman, the senior author and a professor of building technology and mechanical engineering at MIT who has been studying air circulation issues for decades.

The battle between vertical and horizontal

SARS-Cov-2, the virus that causes Covid-19, is largely transmitted in airborne fashion via aerosols, which people exhale, and which can remain in the air for long periods of time if a room is not well-ventilated. Many indoor settings with limited air flow, including classrooms, could thus contain a relatively higher concentration of aerosols, including those exhaled by infected individuals. HVAC systems and open windows can help create “well-mixed” conditions, but in certain scenarios, additional ventilation methods may be needed to minimize SARS-Cov-2 aerosols.

To conduct the study, the researchers used computational fluid dynamics — sophisticated simulations of air flow — to examine 14 different classroom ventilation scenarios, nine involving HVAC systems and five involving open windows. The research team also compared their modeling to past experimental results.

One ideal scenario involves fresh air entering a classroom near ground level and moving steadily higher, until it exits the room through ceiling vents. This process is aided by the fact that hot air rises, and people’s body warmth naturally generates rising “heat plumes,” which carry air toward ceiling vents, at the rate of about 0.15 meters per second.

Given ceiling ventilation, then, the aim is to create upward vertical air movement to cycle air out of the room, while limiting horizontal air movement, which spreads aerosols among seated students.

This is why wearing masks indoors makes sense: Masks limit the horizontal speed of exhaled aerosols, keeping those particles near heat plumes so the aerosols rise vertically, as the researchers observed in their simulations. Normal exhaling creates aerosol speeds of 1 meter per second, and coughing creates still higher speeds — but masks keep that speed low.

“If you wear well-fitting masks, you suppress the velocity of the [breath] exhaust to the point where the air that comes out is carried by the plumes above the individuals,” Glicksman says. “If it’s a loose-fitting mask or no mask at all, the air comes out at a high enough horizontal velocity that it does not get captured by these rising plumes, and rises at much lower rates.”

Two problematic scenarios

But even so, the researchers found, complications can emerge. In their set of simulations focused on closed windows and HVAC use, airflow problems emerged in a simulated classroom in winter, with cold windows on the side. In this case, because the cold air near the windows naturally sinks, it disrupts the overall upward flow of classroom air, despite people’s heat plumes.

“Because of the cold air from the window, some air moves down,” Glicksman says. “What we found in the simulations is, yes, a masked person’s heat plume would rise toward the ceiling, but if a person is close to the window, the aerosols get up to the ceiling and in some cases get captured by that downward flow, and brought down to the breathing level in the room. And we found the colder the window is, the larger this problem is.”

In this scenario, someone infected with Covid-19 sitting near a window would be particularly likely to spread their aerosols around. But there are fixes for this problem: Among other things, placing heaters near cold windows limits their impact on classroom airflow.

In the other set of simulations, involving open windows, additional issues became evident. While open windows are good for fresh air flow overall, the researchers did identify one problematic scenario: Horizontal air movement from open windows aligned with seating rows creates significant aerosol spread.

The researchers suggest a simple fix for this problem: installing window baffles, fittings that can be set to deflect the air downward. By doing this, the cooler fresh air from outside will enter the classroom near the feet of its occupants, and help generate a better overall circulation pattern.

“The advantage is, you bring the clean air in from outside to the floor, and then [by using baffles] you have something that starts to look like displacement ventilation, where again the warm air from individuals will draw the air upward, and it will move toward the ceiling,” Glicksman says. “And again that’s what we found when we did the simulations, the concentration of aerosol was much lower in those cases than if you just allow the air to come in directly horizontally.”

Alejandra Menchaca PhD ’12, a vice president and expert in building science and ventilation at the engineering consulting firm Thornton Thomasetti, calls the research a useful step forward. The paper “provides critical new insight into an aspect of indoor airflow exhaled aerosol dispersal,” says Menchaca, who was not involved in the research. “I hope the [building] industry is able to use these results to enhance its understanding of aerosol dispersal and key variables — many ignored until now — that influence it.”

The energy penalty

In addition to the safety implications during the pandemic, Glicksman notes that better air flow in all classrooms has energy and environmental consequences.

If an HVAC system alone is not creating optimal conditions inside a classroom, the temptation might be to crank up the system full blast, in hopes of creating greater flow. But that is both expensive and environmentally taxing. An alternate approach is to look for classroom-specific solutions — like baffles or the use of high-efficiency filters in the recirculating HVAC air supply.

“The more outside air you bring in, the lower the average concentration of these aerosols will be,” Glicksman says. “But there’s an energy penalty associated with it.”

Glicksman also emphasizes that the current study examines air quality under specific circumstances. The research also took place before the more transmissible Delta variant of the Covid-19 virus became prevalent. This development, Glicksman observes, reinforces the importance of “reducing the aerosol concentration level through masking and higher ventilation rates” throughout a given classroom, and especially underscores that “the local concentration in the breathing zone [near the heads of room occupants] should be minimized.”

And Glicksman emphasizes that it would be useful to have more studies exploring the issues in depth.

“What we’ve done is a limited study for particular forms of geometry in the classroom,” Glicksman says. “It depends to some extent on what the particular conditions are. There is no one simple recipe for better airflow. What this really says is that we would like to see more research done.”

3 Questions: Making the 2021-22 school year work for students

Fri, 08/13/2021 - 12:00am

What’s the best way to get K-12 students across the U.S. to bounce back from the pandemic? MIT’s Justin Reich has an idea: Ask them. Reich, an associate professor in MIT’s program in Comparative Media Studies/Writing and director of the MIT Teaching Systems Lab, has co-authored a new report on the return to the classroom in the 2021-22 school year, based on interviews with over 250 educators and 4,000 students, in addition to 10 charrettes involving students, teachers, parents, and school administrators.

A core finding of the report is that the changes students and teachers would like to make to schools are less about Covid-related issues and more about uncomfortable learning environments, resource deficits, stifling curricula, and overly strict behavioral rules. The report, “Healing, Community, and Humanity: How Students and Teachers Want to Reinvent Schools Post-COVID,” by Reich and Jal Mehta, a professor at the Harvard Graduate School of Education, has just been released; it also contains material readers can use to set up their own interview and research process in schools. Reich notes that the highly transmissible Delta variant of Covid-19 might make a return to normal schooling “a slower process than we had anticipated,” but hopes stakeholders everywhere will keep thinking about how schools can keep evolving. MIT News talked to Reich about the report.

Q: What was the genesis of this study and report?

A: At the beginning of the 2020-2021 school year, the default genre for advice to schools had been the checklist: Here are 175 things you might do to prepare for the coming school year. There’s a purpose to those things, but the obvious missing piece was: What are the two or three most important things school leaders ought to be thinking about? That led us to release our first report in July 2020: “Imagining September: Principles and Design Elements for Ambitious Schools During COVID-19.” Our new report is a follow up to that initial work.

Looking ahead to the coming school year, a consensus narrative has emerged quickly among education policy circles, which is that the problem of the pandemic is that it’s leading to lower test scores, lower levels of math and reading learning as measured by test scores, and the solution to that is targeted tutoring, and extra school programs, and basically just higher dosages of particular schooling modes. That perspective is not entirely wrong, but it is not informed by what students and teachers and their families think. What are they going to say? That’s what we were trying to figure out.

Q: So what are people saying? This report does not have just one conclusion, of course, but what are some of the main findings?

A: First, as I like to say, everyone has been having a different pandemic. The things that worked well for some students worked terribly for others. We heard all kinds of things, from “I learned all kinds of great ways to use technology this year, I’m going to use it more in the future,” to “Everyone is all fed up with using technology, I’m going to use it much less, and get back to face-to-face, in-person kinds of things.” That’s one element.

A second thing is: When we would ask people to reflect on the pandemic and what they wanted to do differently, [sometimes the answers] would feel like they were out of left field. The very first kid in the very first middle school classroom we did this with said, “We should have a pool.” What does a pool have to do with a pandemic? But when you’re working with kids and teachers, they’re telling you what’s meaningful to them, and you have to take their ideas seriously. As terrible as the pandemic was, for a lot of students and teachers, it’s not the most urgent educational concern. The most urgent educational concern is the fact that we have for decades, for over 100 years maybe, allowed these deeply inequitable schools. And some schools have pools and some don’t, and it’s not fair. And some schools have good food, and some schools have lousy food. And some schools treat their students with dignity, and some schools nearly imprison and police their students all day. Those differences are wrong, and that’s what we need to fix. If you go to a poorly resourced school, for some young people the difficulties of the pandemic are not that different than the difficulties that existed before the pandemic.

So if you read three novels instead of four novels this past year, that’s not a good thing, but it’s not the crisis that people closest to classrooms are feeling urgently. There are good reasons to believe kids who missed important learning experiences should have tutoring and extended school days. But also, significantly, for young people, the dominant sense of loss they have is social loss, not learning loss. If you’re 13, or for anyone, missing out on a year of being with people can be devastating. If you want to understand kids this coming year, a dominant feeling is their need to re-establish social connections. And you can fight against that or ignore that, but it’s probably a lot easier to run with that and help meet those needs.

Q: On that note, one theme that is emphasized in this report is that those social and emotional needs are not, in fact, separate from the academic process. Shouldn’t we acknowledge more often that people learn, in school, as part of a community, and that social development can be related to classroom advancement?

A: One thing emerging from the pandemic is a recognition that the application of grace and humanity to our schooling has academic payoffs. One teacher said, “It was just so easy for my kids to leave [online classes], so what was I going to do to make them stay?” Many, many teachers told us there were things they learned this year [about engaging students] that they were going to apply to the future. The paradox of the pandemic is that in one sense teachers feel more agency than before. There are so many things in schools that seemed fixed and immovable that we now realize are changeable. But we have to preserve that sense of possibility.

The way to do that, as a first step, is through reflection, inviting people to think about the last year. They need to do that anyway, to celebrate the extraordinary resilience of young people and educators. So that’s what I’m hoping happens in the coming years, and why we published the report, with a whole series of tools, so more people can do this kind of reflection. There’s exactly one generation of young people who have gone to school in a pandemic, and if we want to do well by them, we need to listen to them.

Why boiling droplets can race across hot oily surfaces

Thu, 08/12/2021 - 5:00pm

When you’re frying something in a skillet and some droplets of water fall into the pan, you may have noticed those droplets skittering around on top of the film of hot oil. Now, that seemingly trivial phenomenon has been analyzed and understood for the first time by researchers at MIT — and may have important implications for microfluidic devices, heat transfer systems, and other useful functions.

A droplet of boiling water on a hot surface will sometimes levitate on a thin vapor film, a well-studied phenomenon called the Leidenfrost effect. Because it is suspended on a cushion of vapor, the droplet can move across the surface with little friction. If the surface is coated with hot oil, which has much greater friction than the vapor film under a Leidenfrost droplet, the hot droplet should be expected to move much more slowly. But, counterintuitively, the series of experiments at MIT has showed that the opposite effect happens: The droplet on oil zooms away much more rapidly than on bare metal.

This effect, which propels droplets across a heated oily surface 10 to 100 times faster than on bare metal, could potentially be used for self-cleaning or de-icing systems, or to propel tiny amounts of liquid through the tiny tubing of microfluidic devices used for biomedical and chemical research and testing. The findings are described today in a paper in the journal Physical Review Letters, written by graduate student Victor Julio Leon and professor of mechanical engineering Kripa Varanasi.

In previous research, Varanasi and his team showed that it would be possible to harness this phenomenon for some of these potential applications, but the new work, producing such high velocities (approximately 50 times faster), could open up even more new uses, Varanasi says.

After long and painstaking analysis, Leon and Varanasi were able to determine the reason for the rapid ejection of these droplets from the hot surface. Under the right conditions of high temperature, oil viscosity, and oil thickness, the oil will form a kind of thin cloak coating the outside of each water droplet. As the droplet heats up, tiny bubbles of vapor form along the interface between the droplet and the oil. Because these minuscule bubbles accumulate randomly along the droplet’s base, asymmetries develop, and the lowered friction under the bubble loosens the droplet’s attachment to the surface and propels it away.

The oily film acts almost like the rubber of a balloon, and when the tiny vapor bubbles burst through, they impart a force and “the balloon just flies off because the air is going out one side, creating a momentum transfer,” Varanasi says. Without the oil cloak, the vapor bubbles would just flow out of the droplet in all directions, preventing self-propulsion, but the cloaking effect holds them in like the skin of the balloon.

The phenomenon sounds simple, but it turns out to depend on a complex interplay between events happening at different timescales.

This newly analyzed self-ejection phenomenon depends on a number of factors, including the droplet size, the thickness and viscosity of the oil film, the thermal conductivity of the surface, the surface tension of the different liquids in the system, the type of oil, and the texture of the surface.

In their experiments, the lowest viscosity of the several oils they tested was about 100 times more viscous than the surrounding air. So, it would have been expected to make bubbles move much more slowly than on the air cushion of the Leidenfrost effect. “That gives an idea of how surprising it is that this droplet is moving faster,” Leon says.

As boiling starts, bubbles will randomly form from some nucleation site that is not right at its center. Bubble formation will increase on that side, leading to the propulsion off in one direction. So far, the researchers have not been able to control the direction of that randomly induced propulsion, but they are now working on some possible ways to control the directionality in the future. “We have ideas of how to trigger the propulsion in controlled directions,” Leon says.

Remarkably, the tests showed that even though the oil film of the surface, which was a silicon wafer, was only 10 to 100 microns thick — about the thickness of a human hair — its behavior didn’t match the equations for a thin film. Instead, because of the vaporization the film, it was actually behaving like an infinitely deep pool of oil. “We were kind of astounded” by that finding, Leon says. While a thin film should have caused it to stick, the virtually infinite pool gave the droplet much lower friction, allowing it to move more rapidly than expected, Leon says.

The effect depends on the fact that the formation of the tiny bubbles is a much more rapid process than the transfer of heat through the oil film, about a thousand times faster, leaving plenty of time for the asymmetries within the droplet to accumulate. When the bubbles of vapor initially form at the oil-water interface, they are  much more insulating that the liquid of the droplet, leading to significant thermal disturbances in the oil film. These disturbances cause the droplet to vibrate, reducing friction and increasing vaporization rate.

It took extreme high-speed photography to reveal the details of this rapid effect, Leon says, using a 100,000 frames per second video camera. “You can actually see the fluctuations on the surface,” Leon says.

Initially, Varanasi says, “we were stumped at multiple levels as to what was going on, because the effect was so unexpected. … It’s a fairly complex answer to what may look seemingly simple, but it really creates this fast propulsion.”

In practice, the effect means that in certain situations, a simple heating of a surface, by the right amount and with the right kind of oily coating, could cause corrosive scaling drops to be cleared from a surface. Further down the line, once the researchers have more control over directionality, the system could potentially substitute for some high-tech pumps in microfluidic devices to propel droplets through the right tubes at the right time. This might be especially useful in microgravity situations, where ordinary pumps don’t function as usual.

It may also be possible to attach a payload to the droplets, creating a kind of microscale robotic delivery system, Varanasi says. And while their tests focused on water droplets, potentially it could apply to many different kinds of liquids and sublimating solids, he says.

The work was supported by the National Science Foundation.