Solar Powered Retinal Implants

An implant that squirts chemicals into the back of your eye may not sound like much fun. But a solar-powered chip that stimulates retinal cells by spraying them with neurotransmitters could restore sight to blind people. Unlike other implants under development that apply an electric charge directly to retinal cells, the device does not cause the cells to heat up. It also uses very little power, so it does not need external batteries. The prototype actuator consists of a flexible silicon disc just 1.5 millimetres in diameter and 15 micrometres thick. When light hits a silicon solar cell next to the disc it produces a voltage. The solar cell is connected to a layer of piezoelectric material called lead zirconate titanate (PZT), which changes shape in response to the voltage, pushing down on the silicon disc. :: New Scientist via Ecofriend


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