Stretchable mesh: The square silicon photodetectors, connected by thin ribbons of metal and polymer, are mounted on a hemisphere-shaped rubber surface. The entire device is able to conform to any curvilinear shape due to the flexibility of the ribbons that connect the silicon islands.
“This technology heralds the advent of a new class of imaging devices with wide-angle fields of view, low distortion, and compact size,” says Takao Someya, a professor of engineering at the University of Tokyo, who was not involved in the research. “I believe this work is a real breakthrough in the field of stretchable electronics.”
Rogers isn’t the first to use the concept of a stretchable electronic mesh, but this work distinguishes itself in that it is not constrained to stretching in limited directions, like other stretchable electronic meshes. And importantly, his is the first stretchable mesh to be implemented in an artificial eye camera.
The camera’s resolution is 256 pixels. At the moment, it’s difficult to improve resolution due to the limitations of the fabrication facilities at the University of Illinois, says Rogers. “At some level, it’s a little frustrating because you have this neat electronic eye and everything’s pixelated,” he says. But his team has sidestepped the problem by taking another cue from biology. The human eye dithers from side to side, constantly capturing snippets of images; the brain pieces the snippets together to form a complete picture. In the same way, Rogers’s team runs a computer program that makes the images crisper by interpolating multiple images taken from different angles.
The most immediate application for these eyeball cameras, says Rogers, is most likely with the military. The simple, compact design could be used in imaging technology in the field, he suggests. And while the concept of an electronic eye conjures up images of eye implants, Rogers says that at this time he is not collaborating with other researchers to make these devices biocompatible. However, he’s not ruling out the possibility in the future.