Researchers at Clemson University are studying ways to make plastic from urine, while another team in China is developing a battery that could one day run on blood. And in Italy, a group has developed a new process that enables spiders to produce silk fibers that are stronger than Kevlar. All in all, it’s been an amazing week for biological ingenuity.
What is it? “IllusionPIN,” a new technology developed by researchers at New York University’s Tandon School of Engineering, can automatically shield the screen of an ATM, smartphone or other electronic device. While the user is able to clearly see the information displayed on the device, anyone more than a few feet away sees something completely different.
Why does it matter? The new technology could protect against “shoulder surfing,” in which a potential thief looks over someone’s shoulder to gain access to sensitive information. By automatically shielding a cellphone’s display from anyone more than a few feet away, IllusionPIN gives an added level of security — not to mention peace of mind. “Our goal was to increase the resilience of PIN authentication without straining the device or compromising user experience,” says Nasir Memon, a member of the research team.
How does it work? IllusionPIN displays two images on the screen, one at high spatial frequency, and one at low spatial frequency, so the image changes, depending on angle at which it’s viewed. “On a device running IllusionPIN, the user — who is closest to the device — sees one configuration of numbers, but someone looking from a distance sees a completely different keypad,” says Memon. The program resets every time a user tries to enter a PIN, making things even harder for shoulder surfers. In trials, researchers found that the technology was 100 percent effective in deterring shoulder surfing attacks.
What is it? Researchers at Clemson University have found a new way to transform human wastes, including urine and carbon dioxide, into nutrients and plastic polymers. The polymers could in turn be used to 3D print new plastic parts.
Why does it matter? The scientists’ research is designed for use in a spacecraft, where every ounce matters, and there isn’t a lot of room for spare parts. “If astronauts are going to make journeys that span several years, we’ll need to find a way to reuse and recycle everything they bring with them,” says team leader Mark A. Blenner. By harnessing the raw materials that astronauts produce, researchers hope to make space missions more self-sufficient — and able to go farther and longer than they have ever gone before.
How does it work? Blenner’s team uses bioengineered yeasts as the key manufacturing ingredients. Some of the microorganisms can consume waste carbon dioxide, while others can consume nitrogen from untreated urine. Using algae to “fix” the nutrients, the yeasts are able to construct polyester polymers, which can be used to make spare parts, and omega-3 fatty acids, a necessary nutrient that will need to be produced on long space trips.
What is it? Scientists at Fudan University in China have developed a tiny, flexible battery that runs on sodium sulfate, a salty, nontoxic solution that is often used as a laxative. Now they’re working on ways to run miniature batteries on other saline fluids — including blood, sweat, tears and even urine.
Why does it matter? Most small batteries use acids or other corrosive chemicals, which can be dangerous if they leak. This is a particularly big problem when it comes to flexible batteries, which are used to power biomedical devices like pacemakers. By using nontoxic fluids, these new flexible batteries eliminate the threat. And, later, if researchers are able to run batteries off fluids that naturally occur in the human body, then patients could even power their own implants.
How does it work? Nontoxic batteries are familiar to anyone who has ever seen a potato clock or a lemon battery: A negative electrode, like a zinc nail, gets stuck in one side of the potato, and a positive electrode, like a copper penny, gets stuck in the other side. When the battery is plugged into a circuit, electrons travel from one electrode to the other through the electrolyte — the potato, in this case — producing current. Fudan University’s new batteries are groundbreaking because of their size and shape. One model looks like a piece of tape, and the other looks like a thread. They are very flexible and durable, which makes them ideal for implanting — and even for other applications, like wearable electric clothing.
What is it? Researchers at the University of Trento, Italy, have developed a new process that enables spiders to produce silk that is up to three times as strong and 10 times as tough as regular webs. “This is the highest fiber toughness discovered to date,” says professor Nicola Pugno, leader of the team.
Why does it matter? These fibers are even stronger than Kevlar, and if spiders could produce them in sufficient quantities, they could be used in hundreds of applications, from body armor to high-strength parachutes. “This paves the way to exploiting the naturally efficient spider spinning process to produce reinforced bionic silk fibres, thus further improving one of the most promising strong materials,” says Pugno.
How does it work? To produce the new spider silk, researchers exposed spiders to liquids containing carbon nanoparticles, which augmented the strength of their natural webs. Pugno thinks that this combination of man-made materials and natural processes could open a new door in innovation. “The natural integration of reinforcements in biological structural materials could also be applied to other animals and plants, leading to a new class of ‘bionicomposites’ for innovative applications,” he says.
What is it? This week, engineers from Drexel University announced that they’ve discovered a way to keep rechargeable lithium-ion batteries from bursting into flame: They’ve added microscopic “nanodiamonds” to the electrolyte mix.
Why does it matter? Lithium-ion batteries have an extremely long lifespan, which makes them very attractive for manufacturers of cellphones, laptops, and other electronic devices. But, as they are repeatedly recharged, there is a risk that they will burst into flame. By reducing that risk, the new nanodiamond batteries could help make thousands of consumer devices much safer — and, in the process, could enable manufacturers to build larger, more complex batteries that can store far more electricity.
How does it work? As lithium-ion batteries are repeatedly recharged, they build up dendrites, little lithium threads that can eventually breach the membrane separating the battery’s positive and negative terminals. When this happens, the battery short circuits, and can ignite its electrolyte solution, causing a fire. When nanodiamonds are added to the mix, they encourage the lithium crystals to grow in an orderly manner, like diamond crystals. Rather than create threads that could damage the battery, the lithium and nanodiamonds make more compact structures, which — because of their structure — can easily slide past each other without doing damage.