Micromachined multifunctional piezoelectric T-beam transducers

Abstract

This paper presents a novel MEMS piezoelectric cantilever beam with a T-shaped cross-section that can be used as both an actuator and a sensor. The micro T-beams are directly micromachined from bulk lead zirconate titanate (PZT) via deep reactive ion etching. The micromachined PZT T-beams are capable of in-plane and out-of-plane motion sensing and actuation via selective activation and measurements at different electrodes. The T-beam structures are tested as flexural actuators and also configured as accelerometers for sensing applications. Nine micromachined T-beams are fabricated and achieve up to 129 μm of out-of-plane displacement, 11.6 μm of in-plane displacement, 694 μN of out-of-plane blocking force, and an average acceleration sensitivity of 30.5 mV/g in 1-4.6 g’s range at a frequency of 1.3 kHz.