Pull apart any electrical device and you will find a riot of right angles, straight lines and flat, uncompromising silicon wafers. John Rogers is changing that. The 45-year-old materials scientist has spent more than 15 years developing electronics that can bend and stretch without breaking. His devices, from surgical sutures that monitor skin temperature to biodegradable sensors that dissolve when their useful life is done, share a unifying quality: They can slip seamlessly into the soft, moist, moving conditions of the living world.
Other scientists construct flexible electronics from innately bendy materials such as graphene, a lattice of pure carbon only one atom thick. From his lab at the University of Illinois at Urbana-Champaign, Rogers has bucked the trend, building most of his devices from silicon, a normally rigid material — but one that, due to widespread use and desirable attributes such as outstanding thermal conductivity, has a track record of efficiency and low cost.
Rogers’ team has tapped silicon’s rep for reliability by tricking it into a more malleable form. Rather than making transistors from conventional silicon wafers, they slice the material into sheets several times thinner than a human hair. “At this scale,” Rogers says, “something that would otherwise be brittle is completely floppy.”
Riding this approach, Rogers has filed dozens of patents and launched five companies to get his products off the ground. His Cambridge, Mass., company MC10 is developing sensors that can fit the contours of the brain or heart to monitor for early signs of epileptic seizures or heart arrhythmias. North Carolina-based Semprius is making ultra-efficient solar cells as thin as a pencil tip and flexible enough to roll into a tube or print on plastic or cloth.
With all his devices, including the five spotlighted here, Rogers’ goal is to make a lasting impact. “If we were successful beyond our wildest dreams,” he says, it’s important that people would care.
