A wireless millimetre-scale implantable neural stimulator with ultrasonically powered bidirectional communication.

Clinically approved neural stimulators are limited by battery requirements, as well as by their large size compared with the stimulation targets. Here, we describe a wireless, leadless and battery-free implantable neural stimulator that is 1.7 mm and that incorporates a piezoceramic transducer, an energy-storage capacitor and an integrated circuit.