This Enzyme’s Hungry For Plastic
What is it? Researchers at the United Kingdom’s University of Portsmouth have discovered an enzyme that can help break down plastics — particularly polyethylene terephthalate, or PET, the material used for soft-drink bottles.
Why does it matter? In other recent plastics news, the agglomeration of seaborne junk known as the Great Pacific garbage patch is “rapidly accumulating plastic,” according to a new study. Humankind could use a good way of disposing of all that junk, so this particular enzyme comes along not a moment too soon. “Plastics have become essential to modern society, driven by their incredible versatility coupled to low production costs,” the Portsmouth team writes in the Proceedings of the National Academy of Sciences. “It is, however, now widely recognized that plastics pose a dire global pollution threat, especially in marine ecosystems.” Currently plastics can be recycled into opaque fibers, used for carpeting and clothing. But the new enzyme raises the possibility of breaking plastic down to its constituent parts and, essentially, starting from scratch — making a brand-new clear plastic bottle from an old clear plastic bottle, rather than using fossil-fuel resources to create original plastic.
How does it work? Led by John McGeehan, the Portsmouth team built off earlier research conducted by Japanese scientists, who in 2016 announced the discovery of the first bacterium evolved to eat plastic — which they discovered, naturally, munching away at a garbage dump. Using an X-ray beam 10 billion times brighter than the sun, which can illuminate individual atoms, McGeehan’s team sought to map the structure of the enzyme the bug produced. Tweaking its structure in the process, the team found they’d accidentally fixed the enzyme to become a particularly efficient plastic eater — 20 percent better. “It’s incredible because it tells us that the enzyme is not yet optimized,” McGeehan told the Guardian.
Your Computer Wastes Energy. Can It Create It, Too?
What is it? Engineers have developed a thin film that can absorb excess heat — the kind that radiates from computers and other electronic devices — and transform it into usable energy.Why does it matter? According to a release from the University of California, Berkeley, where the new technology was developed, “Nearly 70 percent of the energy produced in the United States each year is wasted as heat” — not just from computers but also cars and industrial processes. Being able to harness that heat would mean making more efficient use of the energy we’re already producing. UC materials science and engineer professor Lane Martin, senior author of a paper just published in Nature Materials, said, “We know we need new energy sources, but we also need to do better at utilizing the energy we already have. These thin films can help us squeeze more energy than we do today out of every source of energy.”
How does it work? Via a process called pyroelectric energy conversion, which UC says is “well suited for tapping into waste-heat energy supplies below 100 degrees Celsius, called low-quality waste heat.” Pyroelectricity is the charge released by a material’s change in temperature, whether heating or cooling — the transition these scientists were aiming to harness. The film, which is less than 100 nanometers thick — by comparison, a human hair is between 80,000 and 100,000 nanometers — “can turn waste heat into useable energy with higher energy density, power density and efficiency levels than other forms of pyroelectric energy conversion,” reports UC. While the film’s most immediate application is high-speed electronic devices, the team that developed the technology thinks it could have a wide range of industrial uses; they say the next step is to optimize the film to work on a variety of waste-heat streams.
A Walking, Talking Solar Panel
What is it? In Japan, a joint team from Riken Research and Toray Industries created an ultrathin, flexible organic solar cell that can be heat-printed onto clothing — attached to a T-shirt, say, via a polyurethane substrate that’s melted on, with no damage to the cell. It’s solar you can wear on your sleeve, literally.
Why does it matter? “Power sources that are flexible enough to be attached onto curved and rough surfaces are one of the most promising solutions to supplying electrical power directly to Internet of Things sensors, wearable sensors, and electronic devices,” the team writes in the Proceedings of the National Academy of Sciences. Their flexible solar cell raises the possibility not just of easier, on-the-go charging of personal devices like smartphones, but eventually of products like tents printed with the solar cells — providing electricity outdoors to survivors of natural disasters, for instance. (Or folks camped out waiting for Beyoncé at Coachella.)
How does it work? The new solar cells are small and startlingly durable: Just 3 micrometers thick, they can be attached to fabric in a process similar to heat printing, can withstand temperatures over 100 degrees Celsius, and can be stretched and folded. They also convert energy more efficiently than previous iterations. There’s still work to do, though, as the cells degrade in the presence of water or oxygen. According to the Japanese newspaper Mainichi, the team hopes to improve the cells’ resilience and make them available in the early 2020s. Team members Takao Someya told the newspaper, “Organic solar cells can be produced cheaply, and we anticipate a large market for the technology.”
Wearing Sunglasses Is Now A Contact Sport
What is it? For years, wearers of standard eyeglasses have had the option of lenses that can darken in bright light. The FDA just approved a new product that makes that option available to contact-lens wearers, too.
Why does it matter? Of Americans between the ages of 12 and 54, 42 percent have myopia and between 5 and 10 percent have hyperopia — and some 40 million Americans wear contact lenses to treat their vision problems. The new tech — called Acuvue Oasys Contact Lenses with Transitions Light Intelligent Technology — makes it possible for those 40 million to wear soft contact lenses in bright light without the help of an extra pair of sunglasses.
How does it work? Just like in regular light-shading glasses, the contacts contain a photochromic additive that, according to the FDA, “adapts the amount of visible light filtered to the eye based on the amount of UV light to which they are exposed.” In bright sunlight this means a “slightly darkened lens” which returns to normal in other conditions. The FDA approval followed trials in which the new contacts showed no effects on vision or driving performance, though some exceptions apply: Folks with dry eyes, frequent eye infections, or inflammation shouldn’t go in for the new product, and — as always — don’t wear your contacts to bed.
Researchers To Mice: Grow A Brain
What is it? There’s really no other way to say it: Scientists implanted miniature human brains into the cortices of mice, and have published the results in the journal Nature Biotechnology. As the science-news site STAT puts it, the report marks “the first publication describing the successful implant of human cerebral organoids into the brains of another species, with the host brain supplying the lentil-sized mini cerebrums with enough blood and nutrients to keep them alive and developing for months.”
Why does it matter? Being able to grow brain cells outside of the human head is important for understanding human development, including the development of some neurological disorders — and it also marks an “initial step toward using organoids in regenerative medicine,” according to one of the paper’s authors, neuroscientist Michal Stachowiak, who worked on a team from the Salk Institute of Biological Studies.
How does it work? Human brain organoids — also known as mini brains — are created in the lab from stem cells. According to STAT, “The basic recipe takes human stem cells, makes them differentiate into brain cells, and lets them grow into entities a few millimeters across that mimic the structure, cell populations, and even the electrical activity of the full-blown version.” But once they get to a few millimeters, nutrients aren’t able to penetrate all the way inside them, and they stop growing — thus limiting what they’re able to teach researchers. Rodent cortexes, by contrast, provide the brain organoids with all the nutrients they need to keep on keeping on. The scientists genetically engineered the human cells to “express green fluorescent protein,” STAT wrote, meaning “the tiny blobs showed up in brilliant lime through the transparent window that the scientists glued into the mice’s skull.”