Microfabricated PMN-PT on silicon cantilevers with improved static and dynamic piezoelectric actuation: Development, characterization and control

The paper reports a new composite bimorph Piezo-MEMS actuator based on the mono-crystalline and high piezoelectric coefficient material PMN-PT. The technology is based on the gold bonding of two bulk materials (PMN-PT and Silicon) followed by the Deep Reactive Ion Etching (DRIE) on the silicon side, leading to an optimized displacement actuator. The process requires an external re-polarization, yet the piezoelectric properties are conserved. The device is characterized then modeled and operated in a closed-loop control. The actuation capabilities results are compared to the ones of a classical PZT-ceramic actuator of equivalent size, demonstrating a 3 to 4 times net gain in terms of displacement range. The dynamics are improved by a factor of 2.5X for the same actuating range. The newly microfabricated actuator is also lighter and compatible with the silicon batch fabrication. Future applications include microrobotics, microassembly, cells and gene manipulation etc.