Acoustic Energy Transfer through Skin Using Capacitive Micromachined Ultrasonic Transducers

This work presents the working principles and results of a Capacitive Micromachined Ultrasonic Transducer (CMUT) for an acoustic energy transfer through skin. At first, the working frequency of the used CMUT device is determined with a measure of its average displacement membranes’ answer to an electric dirac pulse. Then, from an impedance measurement, the device excited with an incident ultrasonic pressure is modelled as a current source in parallel with an impedance. Using this model, an electronic interface is proposed and a battery is experimentally recharged. In the end, the acoustic power transfer supplies an average 25mW power on an immersed battery.