Transverse Interdigitated Electrode Actuation of Homogeneous Bulk PZT

A new method for achieving transverse bending-mode actuation of piezoelectric devices microfabricated from homogeneous layers of bulk lead zirconate titanate (PZT) is presented. The technique, which employs a set of interdigitated electrodes patterned on a single side of the piezoelectric substrate, takes advantage of an engineered electric field gradient within the PZT that can be optimized by selecting an appropriate electrode gap. Bulk PZT cantilevers have been fabricated by micropowder blasting, allowing the actuation technique to be evaluated experimentally and compared against analytical and finite-element-model results. Optimal poling conditions for the microfabricated cantilevers are reported, together with both quasi-static and resonant behaviors of the devices. The transverse interdigitated electrode topology provides a simple method for realizing high-performance bending-mode piezoelectric microactuators from a single homogeneous layer of bulk PZT using a simple two-mask process.