Piezoelectric MEMS: Applications for RF Systems and MM-Scale Robotics
Piezoelectric MEMS (PiezoMEMS) technology can enable integrated solutions for a wide variety of applications including radio and cellular communications systems, biomedical, consumer electronics, and mm-scale robotics. Several piezoelectric materials are of interest for this technology. AlN thin films lead the way in front-end filtering technology with film bulk acoustic resonators (FBAR) currently seeing heavy demand in cellular phones. Another material of keen interest is lead zirconate titanate (PZT) especially for applications requiring low voltage, high stroke, high force actuators. As part of an on-going research activity at the Army Research Laboratory, PiezoMEMS technology using PZT thin films has been developed in the area of RF applications and mm-scale robotics.
Specifically, switches and relays covering a frequency space from DC to the high GHz have been demonstrated for mechanical logic for low power embedded microcontrollers and high frequency phase shifters to enable electronically steerable antennas. PiezoMEMS actuators have also enabled the two degree-of-freedom actuators capable of matching the kinematic performance of insects at the mm-scale. In addition, PiezoMEMS based ultrasonic traveling wave motors have been demonstrated with a stator size ranging from 2 to 3 mm in diameter. These actuators combined/integrated with low power sensors are being developed to enable mm-scale mechanical insect-inspired robotic platforms.