Powering In-Body Nanosensors With Ultrasounds

Embedded nanosensors will be a key feature of emerging medical monitoring systems. Power for these sensors could be harvested from ultrasonic vibrations generated by portable miniature sources and converted to electrical energy by piezoelectric nanowires. This letter analyzes the frequency and intensity of ultrasounds required to power an embedded nanosensor subject to medical safety limits, absorption by human tissue and reflection from interfaces. We calculate input and output power at different levels of energy conversion efficiency. Our analysis suggests that ultrasounds can be a viable source for energy harvesting of in-body nanosensors.