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Category: Materials
Tiny Hair-Like Sensors Could Help Smart Materials React to Their Environments
I have seen the future, and it is cilia. Yes, you read that right: those trillions of tiny hair-like extensions that carpet every inch of your body could bring scientists’ visions of a universal class of “smart” materials that change and adapt when subjected to various stimuli closer to reality. These artificial cilia could one day do everything from testing drugs and monitoring air quality to measuring glucose levels and detecting electromagnetic fields.
While largely ignored over the past century (or, at best, dismissed as being purely vestigial), scientists are finally beginning to appreciate the many vital functions they perform in and outside of our bodies. Much like an antenna or sensor, cilia gather information from their surroundings and react—by activating a cellular process or shutting down cell growth, for example—if something seems amiss. They can also act as miniature roads or railways, carrying dirt, bacteria and other noxious materials out of our lungs or shuttling a fertilized egg from the ovary to the uterus. And, perhaps most importantly, cilia make it possible for us to see, hear, smell, and otherwise feel the outside world.
Now some researchers believe that cilia-like structures could bring their sensory prowess to medicine, environmental monitoring and a number of other fields. Leading the charge is Marek Urban of the University of Southern Mississippi who has created a copolymer film with hair-like filaments that mimics the functions of normal cilia. Read More
Concrete + Extremophile Bacteria = Walls That Repair Themselves
When William McDonough and other pioneers of the sustainable architecture movement first envisioned the concept of living, breathing buildings, it’s safe to say that they probably didn’t have structures teeming with actual living, breathing bacteria in mind. But don’t tell that to Henk Jonkers of Delft University of Technology in the Netherlands. What he and his colleagues have developed—a self-fixing bacteria-concrete hybrid—may do more to propel sustainable architecture into the mainstream than McDonough could have ever hoped for.
While it may sound unheard of, scientists have been pressing bacteria into service in construction for years. The use of mineral-producing bacteria has already been explored in a variety of applications, including the hardening of sand and in repairing cracks in concrete. But there are two problems inherent to this approach. First, the reaction that these bacteria undergo to synthesize calcium carbonate results in the production of ammonium, which is toxic at even moderate concentrations. The other problem is a more prosaic one. Since the bacteria have to be applied manually, a worker or team of workers would have to go out every few weeks to patch up every little crack on every slab of concrete—nearly defeating the purpose of making the repair process simpler and more cost-effective.
Jonkers’ solution was to track down a different bacterial strain that could live happily buried in the concrete for prolonged periods of time. Because the bacteria would be mixed into the concrete from the start, they could immediately nip small cracks in the bud before they had a chance to expand and become exposed to water, rendering them vulnerable to further wear and tear. (Concrete structures are typically reinforced with steel bars, but these can easily become corroded when water seeps into the cracks.) Such a strain would have to endure the high pH environment of concrete and churn out copious amounts of calcium carbonate without also producing large quantities of ammonium. Read More
Virus-Powered Rechargeable Clothing Could be Coming to a Store Near You
In a few years’ time, recharging your handheld PC may be as easy as just slipping it into your back pocket. That is, as long as you don’t mind having a virus cocktail woven into your pair of slacks. Yes, the humble virus–that tiny protein-coated bag of genetic material that we more commonly associate with global pandemics–could replace graphite and lithium iron phosphate as the material of choice with which to build the next generation of customizable, high-powered, lithium-ion batteries.
Despite what you may think, this isn’t actually such an unusual pairing. By virtue of their simple design (most only contain enough genes to encode a few dozen proteins) and infinite capacity for manipulation, viruses have become the favored go-to tool for scientists seeking to explore cellular systems and tinker with their underlying components. Gene therapists have been infecting bacterial, plant, and animal cells with viruses for years in order to shuttle in new genes and repair malfunctioning ones. In one recent application, a team of researchers led by University of Pennsylvania ophthalmologist Arthur Cideciyan restored sight to two blind individuals by injecting a virus equipped with a retinal gene into their eyes. Read More
WiFi Medicine: Implantable Biosensors That Could E-mail Your Doctor
Having already become a ubiquitous part of our mobile-centric daily lives, wireless technologies are now poised to slip inside our bodies. Researchers and companies around the world are designing the next generation of biosensors—implantable microchip-like devices that can monitor a patient’s health and ping doctors on their smartphones or computers if something is amiss. One day, some of these devices could even apply short-term fixes or treat disorders outright.
The major challenge that scientists face is developing a sensor that is both long-lived and biocompatible. The human body is extremely picky about implants, and will quickly reject or react poorly to most materials found in everyday electronics. Even the materials that make peace with the body’s immune system, like those found in pacemakers, are not always ideal. Some require constant maintenance, while others need to be replaced every few days and are inconvenient to install, to say the least.
Stealth Fighters of Tomorrow Could Make Today's Look Like the Goodyear Blimp
Blacker than Neo’s leather jacket, blacker than Emperor Palpatine’s black heart, blacker than the mood of Dark City: Nothing is blacker than the thin mesh of 35-nanometer silver wires on a wafer of aluminum oxide unveiled last month at the Conference on Lasers and Electro-Optics.
The composition was imagined by Evegenii Narimanov, a materials engineer at Purdue University, and then created by Mikhail Noginov, a materials physicist at Norfolk State University. (Narimanov recently made some news when he produced the first electromagnetic black hole, capable of slurping up the light waves that come near it.) The mesh is placed at intervals smaller than the wavelength of the radiation it needs to be absorbed. The new material reflected as little as less than one percent of the sub-infrared, 900-nanometer-wavelength radiation, though Narimanov said the effect would be the same at any wavelength —- including the visible light spectrum —- under other configurations. Narimanov told New Scientist he anticipates the material will find its use in coating stealth fighters to improve their invisibility to radar.
Codex Futurius: When Houses Grow on Trees
Yes. It’s true. After a little summer slow-down, it is time for the return of the Codex Futurius, this blog’s never-ending quest to explore the big science of science fiction. This question on futuristic materials was fielded by Sidney Perkowitz, a physicist at Emory University. Thanks much to Dr. Perkowitz for the solid (ha) info and to Jennifer Ouellette, the director the NAS’ Science and Entertainment Exchange (SEEx) program, for connecting us with him.
Will we use metal in the future? What else would we build things out of? Might we use organic technology (machines and buildings made of or from biological organisms) instead?”
In The Graduate, that iconic film from 1967, bewildered 20-something Benjamin Braddock (Dustin Hoffman) gets some career advice from a businessman who leans close and intones “I want to say one word to you. Just one word. Are you listening? Plastics.” Benjamin didn’t follow that advice, but the rest of the world did, and in spades. By 1979, global production of plastic had exceeded that of steel and is still growing, reaching over 200 million tons this year. There’s no doubt that plastic will continue to play a major role in how we make things, but it won’t replace everything.
In some ways, plastic is the material of the future, the latest step in humanity’s long upward trek through the ages of stone, bronze, iron, and steel. The word “plastic” comes from Greek roots meaning “capable of being molded.” Compared to metals and other materials, plastic is infinitely versatile. With its ability to shape-shift and to take on different mechanical and optical properties, it shows up in a huge spectrum of applications from packaging and plumbing to toys, medical supplies, and computers. And unlike iron and steel, plastic doesn’t rust.
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