Photovoltaic Retinal Implants Are Powered By The Images They See
The idea of restoring sight to people with damaged or degenerating photoreceptors in their eyes is simple enough in concept -- place a photoreceptor implant in the eye and beam video from a camera to the implant, bypassing the faulty photoreceptors. However, powering a device implanted in the back of a person's eye indefinitely is a serious obstacle. But Stanford researchers have worked around the problem by beaming images to the implant by pulsing near-infrared light that delivers both data and power to the implanted chip. The 3-millimeter-wide implant is designed like an array of miniature solar cells configured in three layers that are 30 micrometers thick altogether. The array is essentially a collection of pixels, each connected to the next by 300-nanometer-thick silicon joints that allow the array to curve along the natural shape of the retina. To put it another way, the implant is flexible and extremely...