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Micro-Positioning Stages for Adaptive Optics Based on Piezoelectric Thick Film Actuators
S. Gebhardt, D. Ernst, B. Bramlage, O. Pabst, A. Oberdörster
Fraunhofer Institute for Ceramic Technologies and Winterbergstr. 28, D-01277 Dresden, Germany
received September 9, 2015, received in revised form November 3, 2015, accepted November 10, 2015
Vol. 6, No. 4, Pages 285-290 DOI: 10.4416/JCST2015-00060
Abstract
Piezoceramic actuators based on thick film technology offer the opportunity of integrated solutions for smart microsystems. Especially in adaptive micro-optics, where the height of devices is limited, outgassing has to be inhibited and complex actuator structures are required, screen-printed actuators are of great interest. The paper highlights our recent research on micro-positioning stages for integration into a plenoptic camera. The first concept is based on through-thickness polarized lead zirconate titanate (PZT) thick films printed on a 45 mm x 44 mm x 0.17 mm LTCC (Low-Temperature Cofired Ceramics) frame with 4-mm-wide legs. Driving with an electrical field of 2 kV/mm resulted in an upright stroke of 115 µm. The second concept combines through-thickness and in-plane polarized thick films on four cantilever beams of an Al2O3-based micro-positioning stage. Because of the combination of d31- and d33-mode of excitation, each cantilever beam will provide an s-shaped bending profile allowing for a planar and tilt-free lift of 130 µm at an electrical field of 1.66 kV/mm. Both actuator concepts were utilized to adjust position of a micro-lens array between main lens and image sensor in a plenoptic camera setup. With that, the working range of the plenoptic camera could be extended.
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Keywords
PZT, thick film, screen printing, actuator, adaptive optics
References
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