In 1985, the Innovative Design Fund placed an ad in Scientific American offering up to $10,000 to support clever prototypes for clothing, home decor, and textiles. William Freeman PhD ’92, then an electrical engineer at Polaroid and now an MIT professor, saw it and submitted a novel idea: a three-sided zipper. Instead of fastening pants, it’d be like a switch that seamlessly flips chairs, tents, and purses between soft and rigid states, making them easier to pack and put together.

Freeman’s blueprint was much like a regular zipper, except triangular. On each side, he nailed a belt to connect narrow wooden “teeth” together. A slider wrapping around the device could be moved up to fasten the three strips into place, straightening them into a triangular tube. His proposal was rejected, but Freeman patented his prototype and stored it in his garage in the hopes it might come in handy one day.

Nearly 40 years later, MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) researchers wanted to revive the project to create items with “tunable stiffness.” Prior attempts to adjust that weren’t easily reversible or required manual assembly, so CSAIL built an automated design tool and adaptable fastener called the “Y-zipper.” The scientists’ software program helps users customize three-sided zippers, which it then builds on its own in a 3D printer using plastics. These devices can be attached or embedded into camping equipment, medical gear, robots, and art installations for more convenient assembly.

“A regular zipper is great for closing up flat objects, like a jacket, but Freeman ideated something more dynamic. Using current fabrication technology, his mechanism can transform more complex items,” says MIT postdoc and CSAIL researcher Jiaji Li, who is a lead author on an open-access paper presenting the project. “We’ve developed a process that builds objects you can rapidly shift from flexible to rigid, and you can be confident they’ll work in the real world.”

Why zippers?

Users can customize how the fasteners look when they’re zipped up in CSAIL’s software program; they can select the length of each strip, as well as the direction and angle at which they’ll bend. They can also choose from one of four motion “primitives” to select how the zipper will appear when it’s zipped up: straight, bent (similar to an arch), coiled (resembling a spring), or twisted (looks like screws).

The Y-zipper that results will appear to “shape-shift” in the real world. When unzipped, it can look like a squid with three sprawling tentacles, and when you close it up, it becomes a more compact structure (like a rod, for instance). This flexibility could be useful when you’re traveling — take pitching a tent, for example. The process can take up to six minutes to do alone, but with the Y-zipper’s help, it can be done in one minute and 20 seconds. You simply attach each arm to a side of the tent, supporting the structure from the top so that the zipper seemingly pops the canopy into place. 

This seamless transition could also unlock more flexible wearables, often useful in medical scenarios. The team wrapped the Y-zipper around a wrist cast, so that a user could loosen it during the day, and zip it up at night to prevent further injuries. In turn, a seemingly stiff device can be made more comfortable, adjusting to a patient’s needs.

The system can also aid users in crafting technology that moves at the push of a button. One can attach a motor to the Y-zipper after fabrication to automate the zipping process, which helps build things like an adaptive robotic quadruped. The robot could potentially change the size of its legs, tightening up into taller limbs and unzipping when it needs to be lower to the ground. Eventually, such rapid adjustments could help the robot explore the uneven terrain of places like canyons or forests. Actuated Y-zippers can also build dynamic art installations — for example, the team created a long, winding flower that “bloomed” thanks to a static motor zipping up the device.

Mastering the material

While Li and his colleagues saw the creative potential of the Y-zipper, it wasn’t yet clear how durable it would be. Could they sustain daily use?

The team ran a series of stress tests to find out. First, they evaluated the strength and flexibility of polylactic acid (PLA) and thermoplastic polyurethane (TPU), two plastics commonly used in 3D printing. Using a machine that bent the Y-zippers down, they found that PLA could handle heavier loads, while TPU was more pliable.

In another experiment, CSAIL researchers used an actuator to continuously open and close the Y-zipper to see how long it’d take to snap. Some 18,000 cycles of zipping and unzipping later, they finally broke. Y-zipper’s secret to durability, according to 3D simulations: its elastic structure, which helps distribute the stress of heavy loads.

Despite these findings, Li envisions an even more durable three-sided zipper using stronger materials, like metal. They may also make the zippers bigger for larger-scale projects, but that’s not yet possible with their current 3D printing platform.

Jiaji also notes that some applications remain unexplored, like space exploration, wherein Y-zipper’s tentacles could be built into a spacecraft to grab nearby rock samples. Likewise, the zippers could be embedded into structures that can be assembled rapidly, helping relief workers quickly set up shelters or medical tents during natural disasters and rescues.

“Reimagining an everyday zipper to tackle 3D morphological transitions is a brilliant approach to dynamic assembly,” says Zhejiang University assistant professor Guanyun Wang, who wasn’t involved in the paper. “More importantly, it effectively bridges the gap between soft and rigid states, offering a highly scalable and innovative fabrication approach that will greatly benefit the future design of embodied intelligence.”

Li and Freeman wrote the paper with Tianjin University PhD student Xiang Chang and MIT CSAIL colleagues: PhD student Maxine Perroni-Scharf; undergraduate Dingning Cao; recent visiting researchers Mingming Li (Zhejiang University), Jeremy Mrzyglocki (Technical University of Munich), and Takumi Yamamoto (Keio University); and MIT Associate Professor Stefanie Mueller, who is a CSAIL principal investigator and senior author on the work. Their research was supported, in part, by a postdoctoral research fellowship from Zhejiang University and the MIT-GIST Program.

The researchers’ work was presented at the ACM’s ​​Computer-Human Interaction (CHI) conference on Human Factors in Computing Systems in April.

The Department of Homeland Security tried to obtain a Canadian man’s location information, activity logs, and other identifying information from Google after he criticized the Trump administration online following the killings of Renee Good and Alex Pretti by federal immigration agents in Minneapolis early this year.

Lawyers for the man, who has not been named, are alarmed in part because they say that the man has not entered the United States in more than a decade. “I don’t know what the government knows about our client’s residence, but it’s clear that the government isn’t stopping to find out,” says Michael Perloff, a senior staff attorney at the American Civil Liberties Union of the District of Columbia who is representing the man in a lawsuit against Markwayne Mullin, the secretary of DHS, over the summons. The lawsuit alleges that DHS violated the customs law that gives the agency the power to request records from businesses and other parties.

Perloff argues that the government is using the fact that big tech companies are based in the US to request information it would not otherwise be able to get. “It’s using that geographic fact to get information that otherwise would be totally outside of its jurisdiction,” he says. “I mean, we’re talking about the physical movements of a person who lives in Canada.”

DHS and Google did not immediately respond to a request for comment.

The demand for the man’s location data was included in a request DHS issued to Google called a customs summons, which is supposed to be used to investigate issues related to importing goods and collecting customs duties.

“It says right in the statute, it’s for records and testimony about the correctness of an entry, the liability of a person for duties, taxes, and fees, you know, compliance with basic customs laws,” says Chris Duncan, a former assistant chief counsel for US Customs and Border Protection who now works as a private-practice attorney representing importers and exporters. “And that’s all it was ever envisioned to be used for.”

A customs summons is a type of administrative subpoena and is not reviewed by a judge or grand jury before being sent out. According to the complaint, Google alerted the man about the request on February 9, despite an ask included in the summons “not to disclose the existence of this summons for an indefinite period of time.”

Through his attorneys, the man told WIRED he initially mistook the notification for a joke or scam before realizing it was real.

The summons, which is included in the complaint, does not give a specific reason for why the man was under investigation beyond citing the Tariff Act of 1930. The man’s lawyers contend that he did not export or import anything from the United States between September 1, 2025, to February 4, 2026, the time frame the government requested information about.

Instead, the man’s lawyers allege, the summons was filed in response to the man’s online activities, including posts that he made condemning immigration enforcement agents after the killings of Good and Pretti in January.

The man tells WIRED that watching members of the Trump administration “smear these two souls as terrorists was absolutely disgusting and enraging. People were being asked to disbelieve our own eyes so that the men responsible for killing two good Americans would go free.”

The man says of his online activity, “I felt I needed to do something that would stand out and be seen by despairing Americans to show them they had support and that they were not alone.”

When you think of Star Wars, you think of lightsabers. Right? What could be better, from a movie-making standpoint, than a futuristic sword that lets you create awesome fencing duels like in old-time Errol Flynn swashbucklers. (So much better than watching Stormtroopers fire their blasters into walls and ceilings and anything else except their targets.)

Lightsabers come in a cosmic rainbow of hues (color-coded blue or green for good guys, red for bad) and a variety of shapes. There’s even a double-bladed version in Phantom Menace. (I don’t want to start a nerd fight—yet—but the best lightsaber battle in the canon has to be the “Duel of the Fates” in that movie, thanks to the skills and scariness of Darth Maul actor Ray Park.)

So … exactly what are lightsabers? Of course, they aren’t real, so nobody really knows how they work. Even the characters in the movies seem a little confused about it. In Phantom Menace, Anakin calls it a “laser sword.” Yeah, he was a kid, but both Din Djarin (the Mandalorian) and Luke Skywalker also refer to it as a laser sword—though I suspect Luke was being sarcastic.

Anyway, that’s just wrong: It can’t be a laser. For starters, lasers beams are invisible from the side, so you wouldn’t see a thing unless you staged the duels in a disco with fog machines to scatter the beams. Second, the beams go on forever; they don’t have an end. Third, laser beams can’t clank together like swords—they’d just pass through each other when you try to parry.

But what is it then? We can greatly narrow the possibilities by asking if the blade has mass. If it’s some kind of light (as you’d think from the name “lightsaber”), then the answer is no—light, or electromagnetic radiation, has no mass. If we can determine that it has mass, then it’s not light.

This is a question we can answer, by analyzing how lightsabers move when you wave them around. In other words, it’s time for some physics!

Mass and Motion

Don’t confuse mass and weight. Mass is a measure of how much “stuff” like protons, neutrons, and electrons are in an object, and weight is the amount of gravitational force acting on an object. Here we want to see what impact the mass of a lightsaber would have on its motion. But let’s start with something simpler.

Instead of a lightsaber, say we have a “lightball” made of the same buzzy substance. Since it’s symmetrical, we can describe its motion without worrying about rotation. If we want to move this ball back and forth, we call on Newton’s second law of motion. This says the acceleration (a) of an object depends on its mass (m) and the amount of force (F) applied to it.