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.

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Since February, the Firefox team has been working around the clock using frontier AI models to find and fix latent security vulnerabilities in the browser. We wrote previously about our collaboration with Anthropic to scan Firefox with Opus 4.6, which led to fixes for 22 security-sensitive bugs in Firefox 148.

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Nature Climate Change, Published online: 29 April 2026; doi:10.1038/s41558-026-02627-8

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If you want to overthrow Big Tech, you’ll need Section 230. The paradigm shift being built with the Open Social Web can put communities back in control of social media infrastructure, and finally end our dependency on enshitified corporate giants. But while these incumbents can overcome multimillion-dollar lawsuits, the small host revolution could be picked off one by one without the protections offered by 230.

The internet as we know it is built on Section 230, a law from the 90s that generally says internet users are legally responsible for their own speech — not the services hosting their speech. The purpose of 230 was to enable diverse forums for speech online, which defined the early internet. These scattered online communities have since been largely captured by a handful of multi-billion dollar companies that found profit in controlling your voice online. While critics are rightly concerned about this new corporate influence and surveillance, some look to diminishing Section 230 as the nuclear option to regain control. 

The thing is, that would be a huge gift to Big Tech, and detrimental to our best shot at actually undermining corporate and state control of speech online. 

Dethroning Big Tech

We’re fed up with legacy social media trapping us in walled gardens, where the world's biggest companies like Google and Meta call the shots. Our communities, and our voices, are being held hostage as billionaires’ platforms surveil, betray, and censor us. We’re not alone in this frustration, and fortunately, people are collaborating globally to build another way forward: the Open Social Web. 

This new infrastructure puts the public’s interest first by reclaiming the principles of interoperability and decentralization from the early internet. In short, it puts protocols over platforms and lets people own their connections with others. Whether you choose a Fediverse app like Mastodon or an ATmosphere app like Bluesky, your audience and community stay within reach. It’s a vision of social media akin to our lives offline: you decide who to be in touch with and how, and no central authority can threaten to snuff out those connections. It’s social media for humans, not advertisers and authoritarians.

Behind that vision is a beautiful mess of protocols bringing the open social media web to life. Each protocol is a unique language for applications, determining how and where messages are sent. While this means there is great variety to these projects, it also means everyone who spins up a server, develops an app, or otherwise hosts others’ speech has skin in the game when it comes to defending Section 230.

What exactly is Section 230?

Section 230 protects freedom of expression online by protecting US intermediaries that make the internet work. Passed in 1996 to preserve the new bubbling communities online, 230 enshrined important protections for free expression and the ability to block or filter speech you don’t want on your site. One portion is credited as the “26 words that created the internet”:

“No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider.” 

In other words, this bipartisan law recognizes that speech online relies on intermediaries — services that deliver messages between users — and holding them potentially liable for any message they deliver would only stifle that speech. Intuitively, when harmful speech occurs, the speaker should be the one held accountable. The effect is that most civil suits against users and services based on others' speech can quickly be dismissed, avoiding the most expensive parts of civil litigation. 

Section 230 was never a license to host anything online, however. It does not protect companies that create illegal or harmful content. Nor does Section 230 protect companies from intellectual property claims. 

What Section 230 has enabled, however, is the freedom and flexibility for online communities to self-organize. Without the specter of one bad actor exposing the host(s) to serious legal threats, intermediaries can moderate how they see fit or even defer to volunteers within these communities.

Why the Open Social Web Needs Section 230

The superpower of decentralized systems like the Fediverse is the ability for thousands of small hosts to each shoulder some of the burdens of hosting. No single site can assert itself as a necessary intermediary for everyone; instead, all must collaborate to ensure messages reach the intended audience. The result is something superior to any one design or mandate. It is an ecosystem that is greater than the sum of its parts, resilient to disruptions, and free to experiment with different approaches to community governance.

The open social web’s kryptonite though, is the liability participants can face as intermediaries. The greater the potential liability, the more interference from powerful interests in the form of legal threats, more monetary costs, and less space for nuance in moderation. And in practice, participants may simply stop hosting to avoid those risks. The end result is only the biggest and most resourced options can survive.

This isn’t just about the hosts in the Open Social Web, like Mastodon instances or Bluesky PDSes. In the U.S., Section 230’s protections extend to internet users when they distribute another person’s speech. For example, Section 230 protects a user who forwards an email with a defamatory statement. On the open social web, that means when you pass along a message to others through sharing, boosting, and quoting, you’re not liable for the other user’s speech. The alternative would be a web where one misclick could open you up to a defamation lawsuit.

Section 230 also applies to the infrastructure stack, too, like Internet service providers, content delivery networks, domain, and hosting providers. Protections even extend to the new experimental infrastructures of decentralized mesh networks.

Beyond the existential risks to the feasibility of indie decentralized projects in the United States, weakening 230 protections would also make services worse. Being able to customize your social media experience from highly curated to totally laissez-faire in the open social web is only possible when the law allows space for private experiments in moderation approaches. The algorithmically driven firehose forced on users by antiquated social media giants is driven by the financial interests of advertisers, and would only be more tightly controlled in a post-230 world.

Defending 230

Laws aimed at changing 230 protections put decentralized projects like the open social web in a uniquely precarious position. That is why we urge lawmakers to take careful consideration of these impacts. It is also why the proponents and builders of a better web must be vigilant defenders of the legal tools that make their work possible. 

The open social web embodies what we are protecting with Section 230. It’s our best chance at building a truly democratic public interest internet, where communities are in control.

Under a microscope, a bouquet of lollipop-like structures, each smaller than a grain of sand, waves gently in a petri dish of liquid. Suddenly, they snap together, like the jaws of a Venus flytrap, as a scientist waves a small magnet over the dish. What was previously an assemblage of tiny passive structures has transformed instantly into an active robotic gripper.

The lollipop gripper is one demonstration of a new type of soft magnetic hydrogel developed by engineers at MIT and their collaborators at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and the University of Cincinnati. In a study appearing today in the journal Matter, the MIT team reports on a new method to print and fabricate the gel, which can be made into complex, magnetically activated three-dimensional structures.

The new gel could be the basis for soft, microscopic, magnetically responsive robots and materials. Such magno-bots could be used in medicine, for instance to release drugs or grab biopsies when directed by an external magnet.

Making objects move with magnets is nothing new, at least at the macroscale. We can, for example, wave a refrigerator magnet over a pile of paper clips that will trail the magnet in response. And at the microscale, scientists have designed a variety of magnetic “micro-swimmers” — components that are smaller than a millimeter and can be directed remotely by a magnet to squeeze through small spaces. For the most part, these designs work by mixing magnetic particles into a printable resin and pulling the entire swimmer in the direction of an external magnet.

In contrast, the MIT team’s new material can be made into even more complex and deformable structures with micron-scale precision. These features could enable a magnetic millibot to move individual features and perform more complex maneuvers.

“We can now make a soft, intricate 3D architecture with components that can move and deform in complex ways within the same microscopic structure,” says study author Carlos Portela, the Robert N. Noyce Career Development Associate Professor of Mechanical Engineering at MIT. “For soft microscopic robotics, or stimuli-responsive matter, that could be a game-changing capability.”

The study’s MIT co-authors include graduate students Rachel Sun and Andrew Chen, along with Yiming Ji and Daryl Yee of EPFL and Eric Stewart of the University of Cincinnati.

In a flash

At MIT, Portela’s group develops new metamaterials — materials engineered with unique, microscopic architectures that give rise to beyond-normal material properties. Portela has fabricated a variety of such metamaterials, including extremely tough and stretchy architectures and designs that can manipulate sound and withstand violent impacts.

Most recently, he’s expanded his research to “programmable” materials, which can be engineered to change their properties in response to stimuli, such as certain chemicals, light, and electric and magnetic fields.

From the team’s perspective, magnetic stimuli stand out from the rest.

“With a magnetically responsive material, we have control at a distance and the response is instantaneous,” says co-lead author Andrew Chen. “We don’t have to wait for a slow chemical reaction or physical process, and we can manipulate the material without touching it.”

For the new study, the team aimed to create a magnetically responsive metamaterial that can be made into structures smaller than a millimeter. Researchers typically fabricate microstructures by using two-photon lithography — a high-resolution 3D printing technique that flashes a laser into a small pool of resin. With repeated flashes, the laser traces a microscopic pattern into the resin, which solidifies into the same pattern, ultimately creating a tiny, three-dimensional structure, layer by layer.

While 3D resin printing produces intricate microstructures, using the same process to print magnetic structures has been a challenge. Researchers have tried to combine the resin with magnetic nanoparticles before printing the mixture. But magnetic particles are essentially bits of metal that inherently scatter light away or agglomerate and sediment unintentionally. Scientists have found that any magnetic particles in the resin can reduce the laser’s power at a given spot and weaken the resulting structure or prevent its printing altogether.

“Directly 3D printing deformable micron-scale structures with a high fraction of magnetic particles is extremely difficult, often involving a tradeoff between magnetic functionality and structural integrity,” says Sun, a co-lead author on the work.

A printed double-dip

The researchers created a new way to fabricate magnetic microstructures, by combining 3D resin printing with a double-dip process. The researchers first applied conventional resin printing to create a microstructure using a typical polymer gel, with no added magnetic particles. Then they dipped the printed gel into a solution containing iron ions, which the gel can absorb. The iron-soaked structure is then dipped again in a second solution of hydroxide ions. The iron ions in the gel bond with the hydroxide ions, creating iron-oxide nanoparticles that are inherently magnetic.

With this new process, the team can print intricate structures smaller than a millimeter, and add magnetic properties to the structures after printing. What’s more, they are able to control how magnetic a structure’s individual features can be. They found that, by tuning the laser’s power as they print certain features, they can set how cross-linked, or “tight” the gel is when printed. The tighter the gel, the fewer magnetic particles it can form. In this way, the researchers can determine how magnetic each tiny feature can be.

“This provides unprecedented design freedom to print multifunctional structures and materials at the microscale,” Sun says.

As a demonstration, the team fabricated ball-and-stick structures resembling tiny lollipops. The structures were less than a millimeter in height, with balls that were smaller than a grain of sand. The researchers printed the lollipops out of polymer gel and infused each ball with different amounts of magnetic particles, giving them various degrees of magnetism. Under a microscope, they observed that when they passed an ordinary refrigerator magnet over the structures, the lollipops pulled toward the magnet in various degrees, in a configuration that mimicked gripping fingers.

“You could imagine a magnetic architecture like this could act as a small robot that you could guide through the body with an external magnet, and it could latch onto something, for instance to take a biopsy,” Portela says. “That is a vision that others can take from this work.”

The team also fabricated a magnetically responsive, “bistable” switch. They first printed a small millimeter-long rectangle of polymer gel and attached to either side four tiny, oar-like magnetic structures. Each oar measured about 8 microns thick — about the size of a red blood cell. When the team applied a magnet on one end of the rectangle, the oars flipped toward the magnet, pulling the rectangle in the same direction and locking it in that position. When the magnet was applied to the other side, the oars flipped again, pulling the rectangle, like a switch, in the opposite direction.

“We think this is a new kind of bistable mechanism that could be used, for instance, in a microfluidic device, as a magnetic valve to open or shut some flow,” Portela says. “For now, we’ve figured out how to fabricate magnetic complex architectures at the microscale and also spatially tune their properties. That opens up a lot of interesting ideas for soft miniature robots going forward.”

This research was supported, in part, by the National Science Foundation and the MathWorks seed grant program.

This work was performed, in part, in the MIT.nano fabrication and characterization facilities.

Two weeks ago, Anthropic announced that its new model, Claude Mythos Preview, can autonomously find and weaponize software vulnerabilities, turning them into working exploits without expert guidance. These were vulnerabilities in key software like operating systems and internet infrastructure that thousands of software developers working on those systems failed to find. This capability will have major security implications, compromising the devices and services we use every day. As a result, Anthropic is not releasing the model to the general public, but instead to a ...

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