A microfabricated and microassembled wireless resonator

Wireless acoustic emission in the kHz range using an untethered resonator is demonstrated. The actuation principle of the resonator is based on the wireless resonant magnetic microactuators developed recently in our group. The key features of the presented device are its wireless nature, its small size, its simple design and fabrication, and its low cost. We present the theory for the magneto-acoustic transduction principle and obtain good agreement with the experimental data. We also show the potential for wireless viscosity sensing by exploiting the shift of the resonant frequency of the resonator in different fluids.