Piezoelectric MEMS deformable mirrors with high-density actuator array

We fabricated piezoelectric MEMS deformable mirror (DM) with high-density actuator array for adaptive optics to realize low-voltage and high-resolution retinal imaging. 61-element actuator array composed of lead zirconate titanate (PZT) thin film was deposited on the mirror diaphragm, and the diaphragm was deformed by applying control voltage onto the individual actuator through lead lines prepared on a polyimide insulating layer with through holes. The deformation characteristics of the fabricated DM were measured with a laser Doppler vibrometer, and independent application of a voltage on the individual actuator was confirmed. We also confirmed relatively large stroke of 0.23 μm under low-voltage of 20 V without displacement hysteresis.