Electromagnetic-acoustic high-Q silicon resonators for liquid phase sensing

Piezoelectric and electrostatic excitation are the standard transduction methods of ultrasonic sensors. However, electromagnetic-acoustic transduction has been demonstrated as a suitable alternative with unique advantages of noncontact excitation and multi-mode vibration in inexpensive materials, such as thin metal plates. We have also demonstrated the use of high-Q silicon membranes as resonator elements. Here, we report on the utilization of these devices as liquid phase sensors for density and viscosity measurements.