Capacitive Micro-machined Ultrasonic Transducers (CMUTs) can be considered a MEMs based structure that can transmit/receive acoustic signals in the ultrasonic range, typically this is found to be any frequency greater than 20kHz. These devices posses large bandwidths.
The basic element of a CMUT is a parallel-plate capacitor. One plate is fixed, the other plate is supported by a flexible membrane. During transmission an alternating voltage is applied between the membrane and the substrate back plate. Vibrations of the membrane are caused by the resulting electrostatic forces sending out ultrasound at the frequency of modulation. When receiving the ultrasonic wave the membrane vibrates which in turn causes a detectable change in capacitance which can be detected.
OnScale has both the power and the flexibility to consider these devices in 3D.
CMUT device in collapse mode operation