A key problem that has to be overcome in designing tiny pressure sensors (as those used in surgical robots) is in finding the optimal combination of resistance and fragility.  To that end, researchers in Singapore and South Korea have built a micro-electromechanical (MEMS) pressure sensor that uses two layers of silicon dioxide with piezoresistive silicon nanowires between them and an outer coating of silicon nitride for stability.  Such sensors could be used to record pulse and heartbeat from a bed mat and several kinds of wearable devices, or to measure movement in sports or physical rehabilitation.   MORE