Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.

MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity. 

The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.

The material’s unique magnetic properties also allow for transistors with built-in memory, which would simplify circuit design and unlock new applications for high-performance electronics.

“People have known about magnets for thousands of years, but there are very limited ways to incorporate magnetism into electronics. We have shown a new way to efficiently utilize magnetism that opens up a lot of possibilities for future applications and research,” says Chung-Tao Chou, an MIT graduate student in the departments of Electrical Engineering and Computer Science (EECS) and Physics, and co-lead author of a paper on this advance.

Chou is joined on the paper by co-lead author Eugene Park, a graduate student in the Department of Materials Science and Engineering (DMSE); Julian Klein, a DMSE research scientist; Josep Ingla-Aynes, a postdoc in the MIT Plasma Science and Fusion Center; Jagadeesh S. Moodera, a senior research scientist in the Department of Physics; and senior authors Frances Ross, TDK Professor in DMSE; and Luqiao Liu, an associate professor in EECS, and a member of the Research Laboratory of Electronics; as well as others at the University of Chemistry and Technology in Prague. The paper appears today in Physical Review Letters.

Overcoming the limits

In an electronic device, silicon semiconductor transistors act like tiny light switches that turn a circuit on and off, or amplify weak signals in a communication system. They do this using a small input voltage.

But a fundamental physical limit of silicon semiconductors prevents a transistor from operating below a certain voltage, which hinders its energy efficiency.

To make more efficient electronics, researchers have spent decades working toward magnetic transistors that utilize electron spin to control the flow of electricity. Electron spin is a fundamental property that enables electrons to behave like tiny magnets.

So far, scientists have mostly been limited to using certain magnetic materials. These lack the favorable electronic properties of semiconductors, constraining device performance.

“In this work, we combine magnetism and semiconductor physics to realize useful spintronic devices,” Liu says.

The researchers replace the silicon in the surface layer of a transistor with chromium sulfur bromide, a two-dimensional material that acts as a magnetic semiconductor.

Due to the material’s structure, researchers can switch between two magnetic states very cleanly. This makes it ideal for use in a transistor that smoothly switches between “on” and “off.”

“One of the biggest challenges we faced was finding the right material. We tried many other materials that didn’t work,” Chou says.

They discovered that changing these magnetic states modifies the material’s electronic properties, enabling low-energy operation. And unlike many other 2D materials, chromium sulfur bromide remains stable in air.

To make a transistor, the researchers pattern electrodes onto a silicon substrate, then carefully align and transfer the 2D material on top. They use tape to pick up a tiny piece of material, only a few tens of nanometers thick, and place it onto the substrate.

“A lot of researchers will use solvents or glue to do the transfer, but transistors require a very clean surface. We eliminate all those risks by simplifying this step,” Chou says.

Leveraging magnetism

This lack of contamination enables their device to outperform existing magnetic transistors. Most others can only create a weak magnetic effect, changing the flow of current by a few percent or less. Their new transistor can switch or amplify the electric current by a factor of 10.

They use an external magnetic field to change the magnetic state of the material, switching the transistor using significantly less energy than would usually be required.

The material also allows them to control the magnetic states with electric current. This is important because engineers cannot apply magnetic fields to individual transistors in an electronic device. They need to control each one electrically.

The material’s magnetic properties could also enable transistors with built-in memory, simplifying the design of logic or memory circuits.

A typical memory device has a magnetic cell to store information and a transistor to read it out. Their method can combine both into one magnetic transistor.

“Now, not only are transistors turning on and off, they are also remembering information. And because we can switch the transistor with greater magnitude, the signal is much stronger so we can read out the information faster, and in a much more reliable way,” Liu says.

Building on this demonstration, the researchers plan to further study the use of electrical current to control the device. They are also working to make their method scalable so they can fabricate arrays of transistors.

This research was supported, in part, by the Semiconductor Research Corporation, the U.S. Defense Advanced Research Projects Agency (DARPA), the U.S. National Science Foundation (NSF), the U.S. Department of Energy, the U.S. Army Research Office, and the Czech Ministry of Education, Youth, and Sports. The work was partially carried out at the MIT.nano facilities.

When Sonya Atalay conducted her doctoral research, she studied pottery in Çatalhöyük, a remarkable ancient site in Turkey. It’s one of the world’s earliest known urban settlements, flourishing by at least 7000 B.C.E.

Yet even as Atalay was conducting field research and writing her doctoral thesis, she was scrutinizing standard archaeological practices, believing the discipline to be in need of an update. Indeed, it’s an issue she had been grappling with going back to her undergraduate days, when she first went to a dig site near Rome.

“When I started doing archaeological work, the local people were labor,” says Atalay, now a professor at MIT. “They came, they cleaned your clothes, they cleaned the dig house, they weren’t thought of as having important connections with the archaeology, and that really bothered me.” 

Surely, she believed, a culture producing the remarkable things worth studying is worth including in that research process, too. As she says, given “their place-based knowledge, it seemed like we should be talking to people about their heritage. They’re the ones who live on or near sites. I started thinking about what archaeology could look like if it included local communities in a meaningful way.” 

Atalay completed her dissertation while continuing to examine how researchers could alter their approach. She has since published articles and books about the subject, worked to introduce new research practices, and today, as an MIT professor, is a leader in the growing field of community-based archaeology, building partnerships between researchers and local residents.

Among other things, Atalay is the director and principal investigator of the Center for Braiding Indigenous Knowledges and Science (CBIKS), a National Science Foundation-backed project that helps train scholars and implement community-oriented work. She is convinced that community-oriented work creates better outcomes in many fields. 

“A community-based approach is highly applicable beyond archaeology and anthropology, outside of the social sciences,” Atalay says. “I think there’s a lot for engineers or designers or folks in a lot of different fields to learn by involving community members in the research process.”

Atalay joined MIT with tenure in 2024, where she is a professor in MIT’s Anthropology Section.

Roll me away

Atalay grew up in Michigan, not far from Detroit, where she was the first person from her family to go to college. Growing up, she hoped to be a physician. 

“I wanted to be a doctor. That’s what I thought I was going to do,” Atalay says. “I wanted to be a pediatrician.” 

But she also developed an interest in ancient history, something she can date to a precise moment. A 4th grade teacher named Barbara Eisman would give Atalay extra reading when Atalay would finish homework early. One day, Eisman produced a book about ancient Greece and Rome. 

“I remember thinking, this is amazing, discovering things I never knew existed,” Atalay says. “And that stuck with me.”

By the time Atalay enrolled at the University of Michigan, she was still planning to become a doctor. But as an undergraduate, she enjoyed taking archaeology electives to such an extent that she simply changed career paths. 

“I loved it and just got so into it,” Atalay says. And Michigan even provided opportunities for undergraduate fieldwork near Rome, although that meant Atalay had to dig deep to finance her first trip to an archaeological site. 

“I worked at a nightclub and put myself through college by bartending,” Atalay says. “I had a motorcycle, so I was tooling around Ann Arbor. Then I sold my motorcycle to buy the plane ticket to go to Rome so I could take part in the archaeological fieldwork.”

“Relationships are the task”

After graduating, Atalay was accepted into the graduate program for anthropology at the University of California at Berkeley, where she earned an MA and then, in 2003, her PhD. While Atalay’s doctoral research focused on the ancient pottery at Çatalhöyük, she maintained a steady interest in helping archaeology evolve. 

And increasingly, she started drawing on her own observations about fieldwork in the U.S., too. Atalay is Native American, and she recognized the same patterns of exclusion and archaeological extraction being applied to the historical study of Native American societies. 

One additional influence in shaping Atalay’s thinking was the North American Graves Protection and Repatriation Act (NAGPRA), passed by the U.S. federal government in 1990. It requires federal institutions to return human remains, sacred objects, and other cultural materials to Native Americans. Seeing the law enacted reinforced to Atalay that progress in this domain is possible. 

“The push for that act was really about Indigenous people standing up for sovereignty. To return what was wrongfully taken and to carry out research in an ethical way moving forward, there has to be trust and partnerships built,” Atalay says. While observing advocates trying to get NAGPRA passed, she adds, “I learned a lot from them.”

Over time, Atalay went on to serve multiple terms on the commission overseeing NAGPRA, first appointed by President George W. Bush and then President Barack Obama. Ultimately, her perspective has been fed by many sources, converging on similar themes.   

“I was really uncomfortable with how local people weren’t involved with studies of their own heritage,” Atalay says. “So I started thinking about what would it look like to truly partner with communities to plan and carry out research. And that’s how I started my first book, trying to set up a model for how to do ethical work in partnership with communities.”

That book, “Community-Based Archaeology: Research with, by, and for Indigenous and Local Communities” was published by the University of California Press in 2012. In her work, Atalay has focused on a range of specific practices, from research development to fieldwork methods and protecting intellectual property rights for Indigenous people. But the starting point for any work, she emphasizes, is relationship-building and the creation of mutual trust. 

“I tell students, ‘Relationships are the task,’” Atalay says. “I know you want to get in there and carry out fieldwork, but the relationships are everything. Sitting down and talking and sharing life stories and developing trust. Those relationships move at the speed of trust. And that takes time to develop. That’s the key piece. And that’s going to lead to good research outcomes.”

Stronger together

After receiving her PhD, Atalay had postdocs at UC Berkeley as well as Stanford University, then joined the faculty at Indiana University. In 2012, Atalay moved to the University of Massachusetts at Amherst, before joining MIT two years ago.

Currently Atalay is working on multiple projects. As director of CBIKS, she is running an organization with eight research “hubs,” where nearly 100 affiliated scholars are working with over 50 Indigenous communities to establish partnerships that advance environmental, and scientific research projects. 

In some cases, the scholars are involved in familiar-seeming archaeological work, while other center projects involve topics such as enhancing salmon farming, clam cultivation, or returning native seeds from museums to tribes in the Southwest, where elders still retain knowledge for their appropriate use and care.

“Our team members across multiple disciplines are learning from each other,” Atalay says. “So archaeologists and heritage management scholars are talking to environmental scientists and team members who study seeds and agriculture.” The NSF sometimes refers to this as ”convergence science.” The center’s name uses the metaphor of braiding, to represent the ways different strands of knowledge can be woven together to form a sturdy whole.

“With braiding, each of the strands retains its integrity, and they’re stronger when they’re brought together,” says Atalay. She is also currently working on another book project, “Braiding Knowledges,” about how the community-based approach can enhance and strengthen research within universities; it is under contract with the University of Arizona Press. 

At MIT, Atalay adds, she is delighted by the range of students who have started taking her classes, begun thinking about applications to all kinds of projects, and who in turn may end up leading innovative, community-oriented projects of their own.

“I would encourage anyone, no matter what field they’re in, to think about working with a community,” Atalay says. “What we’re learning isn’t just about working with Indigenous communities. It’s applicable outside of anthropology, outside of the social sciences. There is a lot you can learn and contribute to society by carrying out research this way, in any number of fields.”

In 2026, the hype for artificial intelligence agents is louder than ever before. These semi-autonomous programs can “think” and execute well-defined tasks in areas like customer service and software development, typically using language models (LMs). But fields like medical diagnosis and scientific discovery require them to inquire about a vast range of solutions in uncertain environments, which LMs struggle with.

Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and Harvard University’s School of Engineering and Applied Sciences (SEAS) peered deeper into LMs to understand their main issues in high-stakes settings. Their test: “Battleship,” a classic guessing game that’s helped cognitive scientists study how humans seek information. 

CSAIL and SEAS scholars added a twist by reframing the game around asking and answering natural language questions. In their “Collaborative Battleship” game, one participant is a “captain” who inquires about where hidden ships are, while their teammate plays the “spotter” by responding to those questions in real-time.

The researchers first had over 40 humans play the game together, collecting their questions and yes-no answers to build the “BattleshipQA” dataset. These results were a helpful point of comparison when the team tested state-of-the-art LMs (like GPT-5) and smaller models (like Llama 4 Scout) on their game. Without training the models beforehand, they found that top LMs can “beat” humans at “Battleship” — that is, complete the game in fewer turns — but smaller systems are far less rational.

The chief issue was that many models are simply not adept at coming up with useful questions. To get LMs to inquire in ways that reveal more information about hidden ships, the researchers gave each model a Monte Carlo inference strategy, which carefully measures the likelihood of different options being correct with each response. The result: AI models that can beat regular players at “Battleship,” regardless of scale.

Perhaps the most striking results were Llama 4 Scout’s gains. As a relatively small LM, it only beat humans 8 percent of the time. But with refinements to its inference strategy, the model reached a “Battleship” win rate of 82 percent versus humans. This careful and efficient style of asking questions also enabled the model to outpace a frontier model (GPT-5), while operating at around 1 percent of its cost.

On top of this improvement, the researchers shrank the gap between humans and LMs in answering questions. While GPT-5 was a reliable spotter that helped models finish games faster, smaller systems had a bad habit of giving the wrong answers about where ships were hidden. The models saw an accuracy boost of 15 percent on average when they began converting questions into code that explicitly tells them how to verify their answers (for example, having the model run a quick search of an area when asked if a ship was there). 

“Today’s language models are primarily optimized to answer complex queries, but it’s less clear whether they learn to ask good questions for themselves,” says MIT PhD student and CSAIL researcher Gabriel Grand SM ’23, who is a lead author on a paper about the work. “Our work shows that asking informative questions depends on the ability to predict and simulate the world. We find that when we give agents access to a ‘world model,’ they ask better questions and make discoveries more efficiently.”

A sea change for LMs

The team’s first focus was getting LMs to ask better questions. By implementing Monte Carlo inference strategies, the LMs reason about potential guesses as individual particles. The ones that appear more valid with each answer from the spotter would be weighted more heavily, sort of like game balls that inflate or deflate each turn. With this more calculated, adaptive approach, the captain could make inquiries that extracted considerably more info from the spotter.

The scientists then turned to the widely used programming language Python to help out AI spotters. Each question the captain asked was automatically converted into an encoded command. For example, a question like, “Is there a ship in column one that spans two rows?” turns into instructions for the spotter LM to search the area in question and assess how wide the digital game piece is. By giving the model clear directions in a language it understands particularly well, each system gave correct answers considerably more often. The lightweight system GPT-4o-mini saw a nearly 30 percent performance bump, for instance, and even the large model Claude 4 Opus jumped about eight points.

“The field has seen a lot of success from ‘auto-formalization’ strategies, in which LMs generate code to verify their solutions,” says senior author Jacob Andreas, an MIT electrical engineering and computer science associate professor and CSAIL principal investigator. “What I find most exciting about this work is that it opens up the possibility of using these techniques to generate better solutions in the first place, by improving LMs’ exploration and information gathering capabilities. We are excited to scale this work up from scientific domains to applications like coding and mathematical problem-solving.”

Let’s play something else

But how would this approach fare in other board games? The team tested their newly equipped LMs at “Guess Who?”, where large and small models skillfully whittled down 100 options to correctly guess which hidden character had been chosen. Llama 4 Scout was successful 30 percent of the time, but after Grand and his colleagues’ tweaks, it completed the task on over 72 percent of its runs. Meanwhile, GPT-4o leapt from 62 percent to 90 percent. GPT-5 was the spotter in each game to ensure questions were answered as accurately as possible.

While LMs have made promising progress in both games, there’s room for improvement. For instance, the models still struggle to answer complex questions, compared to humans. OpenAI researcher, recent Harvard graduate, and coauthor Valerio Pepe adds that “GPT-5 can beat your average ‘Battleship’ player, and gets a hair better with our methods. However, expert players are still hard to beat for all models, unlike in chess, where even top players don’t succeed against AI systems.”

The researchers’ findings show that AI agents have untapped potential in “needle-in-a-haystack” discovery — navigating a massive space of options to find a rare solution to scientific challenges. While improved information-seeking skills would make them excellent research assistants with, say, identifying a compound’s molecular structure, the researchers caution that “Collaborative Battleship” is a somewhat simple test bed. They’d like to test LMs in more complex settings, where the systems have to consider far more options.

Grand also plans to have humans and AI models collaborate to study whether they work better together. The models might also benefit from a bit of fine-tuning on game simulations, and with more computing power, LMs would have more advanced inference capabilities to predict how a game will evolve. 

“As AI systems become more agentic, the hardest problems turn out to be social ones: tracking common ground, resolving misunderstandings, and adapting to different partners over time,” says Robert Hawkins, assistant professor of linguistics at Stanford University, who wasn’t involved in the paper. “This work elegantly captures these phenomena in a controlled collaborative setting, and makes a compelling case that the real bottleneck for AI agents isn’t just the calculation of optimal questions, but the pragmatic reasoning needed to make the most of their answers.”

Grand and Pepe wrote the paper with two CSAIL principal investigators: MIT Associate Professor Jacob Andreas and MIT Professor Joshua Tenenbaum. Their work was supported, in part, by the MIT Siegel Family Quest for Intelligence, the MIT-IBM Watson AI Lab, the FinTechAI@CSAIL initiative, a Sloan Research Fellowship, Intel, the Air Force Office of Scientific Research, the Defense Advanced Research Projects Agency, the Office of Naval Research, and the National Science Foundation. They showcased their paper as an oral presentation at the International Conference on Learning Representations (ICLR) in April.

Tod Machover, the Muriel R. Cooper Professor of Music and Media, faculty director of the MIT Media Lab, and director of the Opera of the Future research group, will receive the George Peabody Medal for Outstanding Contributions to Music and Dance in America — the highest honor bestowed by the Peabody Institute of the Johns Hopkins University. 

As a composer and music tech pioneer, Machover has helped expand music’s possibilities for artists and audiences alike through his work in participatory opera, artificial intelligence, and creative technologies. He joins a roster of previous George Peabody Medal recipients that includes Stevie Wonder, Misty Copeland, Herbie Hancock, Renée Fleming, Yo-Yo Ma, Wynton Marsalis, Ella Fitzgerald, and Leonard Bernstein.

In the citation for the Peabody Medal, Peabody Institute Dean Fred Bronstein writes: “The breadth and depth of Tod Machover’s career — his work in participatory opera, as an educator and faculty director of the MIT Media Lab, his genuinely groundbreaking and prescient work at the intersection of music and technology, along with an overall and broad impact on the American music scene — make him an ideal recipient for the Peabody Medal … Machover continues to provide inspiration especially in the fast-evolving relationship between AI and the creative process. We are honored to welcome to campus a true pioneer and thought leader.”

Hailed as a “musical visionary” and “America’s most wired composer,” Machover is recognized as one of the most innovative composers active today. He is praised for creating music that breaks traditional artistic and cultural boundaries and for developing technologies that expand music’s potential for everyone. 

Machover was the first director of musical research at Pierre Boulez's IRCAM in Paris and was inducted as a fellow of the American Academy of Arts and Sciences in 2024. His work has been recognized by organizations including the American Academy of Arts and Letters, the National Endowment for the Arts, and the French Culture Ministry.

The Peabody Institute, the first music conservatory in the United States, advances a dynamic model of the performing arts, empowering musicians and dancers from diverse backgrounds to create and perform at the highest level. As division of Johns Hopkins University, Peabody provides opportunities for interdisciplinary studies and is a leading voice at the intersection of art and education.

In the United States, children routinely receive an injectable form of the polio vaccine. This vaccine is very effective at preventing illness, but it doesn’t block transmission of the polio virus as well as the oral polio vaccine does.

Poliovirus is usually transmitted through contaminated food or water, so the GI tract is where the body is first exposed. Because the oral vaccine induces a mucosal immune response within the GI tract, it is much more effective at preventing infection and spread of the virus. However, there is a small chance that the oral vaccine can become infectious, so many countries have stopped using it.

Researchers at MIT have now come up with a way to modify the injectable vaccine so that it can also promote a mucosal immune response. This vaccine could help to achieve polio eradication while avoiding the risks of the oral polio vaccine.

“People who are vaccinated with the injectable vaccine are not getting sick, but they may be helping the virus circulate. Mucosal immunity could help lower that shedding and ideally eliminate it,” says Ana Jaklenec, a principal investigator in MIT’s Koch Institute for Integrative Cancer Research.

The researchers’ new vaccine consists of the current injectable, inactivated polio vaccine (IPV), delivered with a nanoparticle-based adjuvant that helps steer immune cells to the mucosal lining of the intestine. In a study of rats, the researchers found that this vaccine produced a 20-fold increase in the type of antibodies needed for mucosal immunity, compared to IPV alone.

Jaklenec and Robert Langer, the David H. Koch Institute Professor at MIT, are the senior authors of the study, which appears today in Science Advances. MIT postdoc Behnaz Eshaghi is the lead author of the paper. 

Targeting polio

Polio, which can cause paralysis in severe cases, is now rare in most of the world due to extensive vaccination campaigns. The virus is highly contagious and is most commonly spread through consumption of food or water contaminated with the stool of an infected person.

Cases are occasionally seen in the United States and other countries, and the virus is endemic in Pakistan and Afghanistan. While most of these cases are caused by the virus spreading among unvaccinated individuals, some cases may be due to the evolution of the live viruses used in the oral polio vaccine (OPV). These viruses are attenuated, meaning they are alive but weakened. In rare cases, they can mutate and evolve to become infectious again.

It’s also possible that wild poliovirus can be spread by people who have received the injected polio vaccine. These people would likely not experience any symptoms, but they could still shed the virus in their stool. Eventually, this could expose someone who isn’t vaccinated. Studies have shown that even in countries that with very high polio vaccination rates, the virus can be detected in wastewater.

To boost the chances of completely eradicating polio, it would be ideal to use a vaccine that cannot evolve to cause infection, like the current injectable IPV, and would also induce mucosal immunity, like the OPV. 

In hopes of achieving that, the MIT researchers teamed up with researchers at Harvard Medical School who have shown that using a derivative of vitamin A as a vaccine adjuvant can help stimulate immune cells to go to the GI tract.

That adjuvant, known as Am80, works well, but to generate a strong response, it needs to be injected for several days in a row, which is not feasible for most vaccine campaigns. 

To eliminate the need for repeated daily injections, the researchers set out to develop a nanoparticle formulation that would enable the adjuvant to be released slowly over several days. They tested several different types of nanoparticles and found that the one that worked best was a lipid nanoparticle (LNP).

“The purpose of the nanoparticle is making sure that we can engineer a platform with a sustained release of the cargo for a few days,” Eshaghi says. “That way we can overcome the bottleneck that for free administration of Am80 you need multiple daily injections.” 

Mucosal immunity

In tests in rats, the researchers delivered an injection of an inactivated polio vaccine, similar to the one that is now used in the United States, along with a separate injection of Am80 encapsulated in LNPs. After the first dose, boosters were given at four weeks and eight weeks.

After injection, the nanoparticles accumulate in the lymph nodes, where they interact with B and T cells that are also exposed to the polio vaccine. This interaction stimulates the B and T cells to produce two surface proteins that act as homing signals directing them to the GI tract.

The B cells also begin producing a type of antibodies called IgA, which protect body surfaces from infection by coating the mucosal membranes. In addition, the rats also produce IgG antibodies that circulate in the bloodstream, similar to the antibodies that are normally produced in response to the injected polio vaccine.

“IPV is a safe vaccine, but it cannot create mucosal immunity. OPV can create that mucosal response, but it is not as safe,” Eshaghi says. “By adding Am80 to lipid nanoparticle as an adjuvant, we are combining the safety of IPV with an adjuvant that can produce the mucosal immunity that normally you can only get with OPV.” 

The researchers now plan to test the vaccine in additional larger animal models, where they will inject the vaccine and adjuvant mixed together.

Using Am80 or other adjuvants to induce a mucosal response could also help researchers design improved vaccines for other pathogens that infect the GI tract, or for diseases that infect the lungs or reproductive tract. 

“You could potentially add it to any vaccine that’s injected,” Jaklenec says. “This particular work shows that cells can be directed to the gut and increase enteric mucosal immunity. Whether it works for the respiratory or vaginal mucosa is not yet clear.”

The research was funded by the Gates Foundation.

With help from a novel cross-linking molecule, MIT chemists have shown they can substantially improve the ballistic impact resistance of common polymers, including polystyrene and a type of rubber used to make shoe soles.

Polystyrene is a hard, glassy polymer that is used to make many types of plastic containers, such as bottles and mugs, as well as disposable cutlery. It is also found in coatings for electronic devices, and its foam form is the basis for Styrofoam and other lightweight packaging. (While sometimes labeled with recycling code No. 6, polystyrene is difficult to recycle and rarely collected for reuse in the U.S.)

To make the polymer more resistant to sudden impact, the MIT team added weak bonds scattered throughout the material as cross-links, which allows the material to dissipate energy much more effectively under deformations. When struck by a projectile, these weak bonds selectively break at the site of impact to open up pathways for enhanced energy absorption.

The researchers found that this approach can also fortify styrene-butadiene-styrene rubber, and they are now investigating whether it will also work for other types of polymers such as latex or the rubber that is used to make tires. 

“These cross-linkers can substantially increase the amount of energy that the material absorbs under ballistic impact. You can imagine many applications of that, especially if this could be generalized to other polymers,”says Jeremiah Johnson, the A. Thomas Geurtin Professor of Chemistry at MIT and a member of the Koch Institute for Integrative Cancer Research.

Johnson and Keith Nelson, the Haslam and Dewey Professor of Chemistry, are the senior authors of the study, which appears today in Nature. Former MIT postdocs Zhen Sang and Suong T. Nguyen and MIT graduate student Kwangwook Ko are the paper’s lead authors.

Tougher plastics

In a study published in 2023, Johnson and colleagues at MIT and Duke University showed that they could make polymers tougher using a counterintuitive strategy: adding weak cross-linkers that are distributed throughout a polymer network. These weak linkages, also called mechanophores, break under tearing conditions in a way that helps preserve the stronger bonds that bear the load, allowing the material to dissipate more energy.

“As a crack starts to propagate through the material, these mechanophores split in two, which helps to dissipate energy and redirect where the crack goes. That means you have to put in more energy to tear the material,” Johnson says. 

Unlike their previous study, which examined toughening under slow tearing conditions, the new Nature study aimed to develop mechanophore-enabled strategies for resisting rapid deformation, such as that caused by sudden impact. The researchers were especially interested in applying the strategy to some of the most widely used polymers, such as polystyrene.

To do that, they developed a way to directly incorporate mechanophores as cross-links into common polymers. Then, they used a system invented by Nelson — laser-induced microprojectile impact testing (LIPIT) — to study how the resulting polymers respond to projectile impacts. With this system, tiny projectiles — silica beads about 10 microns in diameter — are fired at the film at about 750 meters per second (more than 1,600 miles per hour). The amount of energy absorbed by the material can be calculated by measuring the change in the particle’s velocity before and after it passes through the film. 

“We first developed this method to study microparticle impact and penetration into bulk polymer samples, where we would monitor particle propagation through about 100 microns of material and analyze after impact how polymer morphology had changed,” Nelson says. “Our new measurements show how much additional information can be extracted from particle velocities before and after penetration through a thin layer. They also show deeply informative deformation patterns both during particle impact and afterward.”

This technique allowed the researchers to mimic the type of forces that might be seen in the real world when a plastic object is hit with another object, or when you drop your phone on the ground. In their experiments, the researchers showed that mechanophore cross-linked polystyrene was able to absorb substantially more energy from an impact than regular polystyrene.

“It turned out that the mechanophore leads to substantial increases in energy dissipation compared to both uncross-linked and conventionally cross-linked polystyrene, a behavior that had not been observed in related previous work,” Johnson says.

Absorbing impact

To figure out how the mechanophores help make polystyrene more impact resistant, the MIT team enlisted help from collaborators at MIT, Purdue University, Northwestern University, and Duke University. 

Through experiments and simulations, they found that when a high-speed particle strikes the material, it raises the temperature at the impact site high enough to form a mobile zone. In this zone, the mechanophore bonds are selectively broken under force, opening controlled pathways that better absorb the energy of impact while leaving the area beyond the impact site relatively unaffected and stable.

“What is particularly attractive about this approach is the ability to bestow these properties upon ‘off-the-shelf’ commodity plastics, both glassy and elastomeric, with minimal chemistry which makes it in principle quite scalable and relevant. This study combines an elegant approach while providing an in-depth mechanical analysis of the failure mechanism,” says Yoan Simon, an associate professor in the School of Molecular Sciences at Arizona State University, who was not involved in the research.

The researchers also found that they could insert these mechanophores into styrene-butadiene-styrene (SBS) rubber — which is used in shoe soles as well as asphalt and roofing materials — and observe a similar effect. They are now exploring whether this approach could also work with a related material, styrene-butadiene rubber, which is one of the major components of tires. 

If successful, this technology could yield longer-lasting tires and also cut down on the amount of microplastics generated when tires contact the road, which is estimated to account for at least 10 percent of the microplastics in the environment. 

“Materials with energy-absorbing mechanophores could one day help keep your vehicle's tires from blowing out on the highway or provide more protective cases for personal electronics,” says Katharine Covert, program director of the U.S. National Science Foundation Centers for Chemical Innovation, which invested in the team’s research. “This work really demonstrates how valuable new insights can be rapidly generated by bringing together researchers with different areas of expertise.”

The research was funded by the National Science Foundation Center for the Chemistry of Molecularly Optimized Networks, the U.S. Army Research Office through MIT’s Institute for Soldier Nanotechnologies, a Schmidt Science Postdoctoral Fellowship, and the U.S. Air Force Office of Scientific Research.

Researchers are using machine learning algorithms to decrypt historical pencil-and-paper ciphers.

Four other states have passed similar legislation this year. Louisiana's bill wouldn't block coastal erosion litigation against oil companies.

The Republican-backed proposal would impose new regulations on the energy-hungry facilities, as well as set in motion a repeal of the state’s 2050 climate goal.

The Federal Judicial Center says it pulled the climate science guidance because of Republican threats to its federal funding.

The financial infusion will help the Memphis-area facility triple its carbon removal capacity.

Insurance claims increased by $10 billion since 1980 due to the disappearance of those ecosystems.

A 9th U.S. Circuit Court of Appeals panel says the link between the orders to unleash fossil fuel and climate injuries is too speculative.

The label would benchmark the environmental performance of data centers, using metrics including energy and water efficiency, renewable energy use, and waste heat recovery.

Scientists said that the goal puts the U.K. on course to meet its 2050 net-zero target, though Tuesday's announcement doesn't include details of how it will be achieved.

JetBio will rely on a diverse range of suppliers, including makers of sugar, second-crop corn as well as waste-based ethanol, for processing into sustainable aviation fuel.

And when the disaster is over, health experts say, try to restore a sense of normalcy by seeking out support, returning to routines and helping others.

Nature Climate Change, Published online: 03 June 2026; doi:10.1038/s41558-026-02660-7

How hailstorms change with warming is not well understood. Here the authors use global projections with different hail proxies to show that hail-prone conditions shift polewards under warming, also shifting crop risk related to hail hazards.

Nature Climate Change, Published online: 03 June 2026; doi:10.1038/s41558-026-02663-4

The authors assess the impacts of China’s Grassland Ecological Compensation Policy on climate and maize yields. They demonstrate reduced temperature and increased precipitation, which are linked to increased crop yields that partially offset restoration costs.

Nature Climate Change, Published online: 03 June 2026; doi:10.1038/s41558-026-02652-7

The Southern Ocean is important for anthropogenic heat uptake, and this regional analysis shows an area with enhanced warming in the high-latitude Indian sector. Model analyses indicate that mesoscale eddies drive upward heat transport, linked to a strengthening of the Antarctic Circumpolar Current.