Miracle materials able to function as a microprocessor when they’re dry and dissolve into nothing when submerged in water got a lot of press coverage July 16 when researchers posted a video of the dissolving chip in action.
The video, first picked up by the Associated Press, is one of a series of efforts at “transient electronics” that will dissolve at the end of their useful lives so they can be recycled or thrown away without increasing the approximately 720,000 tons of e-waste generated by U.S. consumers and businesses every year.
The video came from the research group led by John Rogers of the University of Illinois Champaign-Urbana, whose other crowd-pleasing innovative uses of advanced materials includes a stretchable lithium-ion battery, a micro-camera modeled on an insect eye, flexible circuits designed to be applied to human skin, and tiny instruments meant to be implanted for medical purposes and then dissolve.
Graphene—a one-atom-thick layer of carbon laid out as a mesh of hexagons that is currently considered the strongest material in the world—is proving to be so versatile it can be used as a heat sink within a chipset, a heat-reducing component within microprocessors, the surface of a touch screen, an integrated circuit able to run at super-high frequencies, and as the material of the circuits and transistors within the processor. It could potentially be used to create superfast processors that move electrons via quantum tunneling rather than through ordinary electrical circuits. It can also be sandwiched between layers of boron nitride to create capacitors able to operate at high frequencies while remaining flexible.
Stacked in layers, different sections of the same chunk of graphene can act as a highly efficient conductor, while the rest acts as a semiconductor insulating the layers that actually convey electricity.
The versatility of flat sheets of graphene may only be the beginning. Researchers at Boston College have synthesized a completely new form of carbon with a host of potential new uses and characteristics, by grossly warping neat sheets of carbon atoms into crumpled, three-dimensional shapes.
Graphene can make lithium-ion batteries store more electricity and act as the raw material fed into 3D printers to create solid objects, flexible sheets or rods that are light, flexible and 200 times the strength of steel. With the right plans and the right printer, a sheet of graphene fed in one end could also come out the other as whole integrated circuits made from the same raw material.
Built into optical switches, graphene could be the basis of superfast processors that work by moving photons rather than electrons. Layered into the transistors, semiconductors and other components of a microprocessor, graphene could allow optically based processor to run at terahertz speeds. Terahertz oscillations are 1,000 times higher in frequency than gigahertz—the frequency range at which current processors operate.
Built into processor for networking gear and using light at infrared wavelengths, it could be made into optically switched networks running at 100 times the top speed of current networking gear.
Products made from graphene are projected to reach $100 million per year by 2018, according to Future Markets. But there’s also something of a catch: according to the most recent research, graphene can be incredibly toxic to humans.
When a microsheet of graphene is broken or torn, it sheds nanoparticles so small they can penetrate most filters. Those particles come with sharp, jagged edges that can slash through the walls of human cells and embed themselves in a destructive layer that may be impossible to remove.
It’s not clear if the effect of graphene shards is primarily physical (like the effect of asbestos inhaled into the lungs) or if there is a chemical toxicity as well. “These materials can be inhaled unintentionally, or they may be intentionally injected or implanted as components of new biomedical technologies. So we want to understand how they interact with cells once inside the body,” according to Robert Hurt, professor of engineering, who co-write a paper in the July 10 Proceedings of the National Academy of Sciences describing the phenomenon.