Measurement on the actuating and sensing capability of a PZT microcantilever

Abstract

PZT thin film devices are very competitive when charge signal and force outputs are demanded. A Pb(Zr0.5Ti0.5)O3 thin film with 24 coating layers is deposited by a sol–gel method. An array of three piezoelectric microcantilevers is fabricated using the wet and dry combined bulk micromachining techniques. Each microcantilever has a two-segment top electrode in different dimensions. The actuating and sensing capability of the six segments on the three microcantilevers are measured. It is proved that the proposed piezoelectric microcantilevers have both actuating and sensing functions; different proportion partition results in the diversity of the actuating and sensing capability. At the same location, the longer the piezoelectric segment is, the stronger actuating and sensing capability it has. The maximum actuating sensitivity and sensing sensitivity before poling treatment are 16.7 µN V−1 and 13.44 pC µm−1, respectively, which become about twice as big after poling. We may choose the appropriate microcantilevers to satisfy our purpose on some specific condition where force feedback and object manipulation are needed simultaneously. A hysteresis phenomenon is encountered in the actuating process while not in the sensing process.