The solar power energy captured is designed for the synthetic skin used around certain limb prosthetics. The idea is to allow the limb to generate its own energy from solar power whilst being fitted to the patient. The innovation comes from Scotland, via Glasgow University. Moreover, this is no ordinary artificial skin, it is an electronic skin for prosthetic hands made with graphene. Graphene, as regular readers of Digital Journal’s science pages will know, is the new super-material. Graphene, in its basic form, is a one-atom thick sheet of carbon. The material is light, transparent, strong and very conductive. One advantage with graphene as a ‘skin’ is its thickness, which, being very thin, allows for heightened sensitivity.
The resultant ‘skin’ is highly sensitive to touch. However, this sensitivity comes at a price and this is the power consumption needed for the skin to function. The early prototypes of the graphene based skin needed a clunky battery. The new innovation replaces the battery with photovoltaic cells located within the skin. Photovoltaics refers to the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect. A typical photovoltaic system employs solar panels, each comprising a number of solar cells; with the case of the new ‘skin’ this is designed on a more micro-scale compared with the typical solar panel.
The use of photovoltaics comes about because of the unusually low thickness of the ‘skin’; the optical transparency allowable from the use of graphene means that 98 percent of the light that strikes its surface will pass directly through, meaning the ‘skin’ is an ideal medium for gathering energy from the sun to generate power.
The inventor of the new solar powered skin, Dr. Ravinder Dahiya, has explained to the BBC: “The real challenge was ‘how can we put skin on top of photo-voltaic and yet allow light to pass through the skin?’ That’s what we have done.”
The outcome is something remarkable: a skin that can generate its own energy together with the power needed to operate it. The full details are contained within a research paper published in Advanced Functional Materials, under the title “Energy Autonomous Flexible and Transparent Tactile Skin.”
