Design, fabrication, and integration of piezoelectric MEMS devices for applications in wireless sensor network

One of the competitive solutions to expand the function of microelectromechanical system (MEMS) is the integration of piezoelectric lead zirconate titanate (PZT) thin films for device self-actuation at low driving voltage, device self-sensing with low power consumption, as well as for energy harvesting. However, up-to-date, difficulties still exist not only in PZT film preparation but also in PZT film integration with other MEMS components and ICs. This paper therefore presents our recent progress on large area deposition, fine pattern etching, and low temperature bonding of PZT thin films for wafer scale PZT film integration and piezoelectric MEMS application. The energy dissipation mechanism in piezoelectric MEMS devices was also discussed to optimize the device structure for the pursuit of better performance. Ultra-sensitive micro cantilever and disk resonator with on-chip piezoelectric PZT transducers were presented herein as an exploratory application of piezoelectric MEMS devices in distributed wireless sensor network.