A 6-DOF piezoelectric micro vibratory stage based on multi-axis distributed-electrode excitation of PZT/Si unimorph T-beams

This paper reports the design, optimization, fabrication and preliminary testing of a six degree of freedom (6-DOF) multi-axis micro vibratory stage leveraging a new type of piezoelectric actuation based on distributed excitation electrodes and PZT/Si unimorph T-beams. This new design concept also allows both angular and linear bending actuation of a single piezoelectric unimorph with very large in-plane and out-of-plane displacements. The PZT/Si beam thickness ratio and width ratio are optimized, and the 6-DOF actuation modes are characterized via FEA. The vibratory stage is fabricated via a process that involves bonding/thinning of bulk-PZT over silicon features and includes PZT micro-patterning via an improved DRIE process. Preliminary tests show static displacement of ±1.0° for X/Y-tilting mode and ±22 μm for Z-translational mode, while the minimum resonance frequency is >0.9 kHz, and the maximum power consumption is <;250 μW. The presented device compares favorably with respect to previously reported multi-axis stages in terms of motion capability, displacement, size, input voltage and power consumption.