Engineers from the University of Glasgow have developed a synthetic skin that could help amputees regain their sense of touch. Clad in graphene, a form of graphite just one atom thick yet tougher than steel, the “electronic skin” even uses photovoltaic cells to harvest power from the sun. “This could allow the creation of an entirely energy-autonomous prosthetic limb,” said Ravinder Dahiya, head of the School of Engineering’s Bendable Electronics and Sensing Technologies group and the author of a paper on the subject in the current issue of Advanced Functional Materials.
Graphene and solar cells are ideal bedfellows because of the former’s unique physical properties, Dahiya said. The material’s optical transparency, for instance, allows 98 percent of the light that hits its surface to pass through. Graphene is also electrically conductive, which means it can channel power to sensors that measure attributes like temperature, pressure, and texture.
“Those measurements mean the prosthetic hand is capable of performing challenging tasks like properly gripping soft materials, which other prosthetics can struggle with,” Dahiya said.
Because the new skin requires only 20 nanowatts of power per square centimeter, even the lowest-rated photovoltaic cell on the market will suffice. The energy generated by the skin’s cells cannot be stored at present, but the researchers are exploring ways of diverting any unused energy into batteries that can be drawn from at a later time.
Beyond prosthetics, the breakthrough could fuel further advances in robotics—a boon for an increasingly automated world.
“Skin capable of touch sensitivity also opens the possibility of creating robots capable of making better decisions about human safety,” Dahiya said. “A robot working on a construction line, for example, is much less likely to accidentally injure a human if it can feel that a person has unexpectedly entered their area of movement and stop before an injury can occur.”