Inventors:
Cheng-Chun Lee - Chungli, TW
Clifford R. Hume - Seattle WA, US
Guozhong Cao - Seattle WA, US
Chuan Luo - Beijing, CN
Assignee:
University of Washington through its Center for Commercialization - Seattle WA
International Classification:
A61F 11/04, H04R 25/00, H02N 2/06
Abstract:
Disclosed are methods and systems for improving actuator performance by reducing tensile stresses in piezoelectric thin films. In one embodiment, a piezoelectric actuator includes a substrate, a first electrode positioned on the substrate, a piezoelectric thin film positioned on the first electrode, and a second electrode positioned on the piezoelectric thin film. The displacement capability of the actuator is enhanced by reducing the tensile stresses of the piezoelectric thin film. In some embodiments, a constant DC voltage applied to the piezoelectric actuator generates compressive in-plane stresses, which counteract the tensile in-plane stresses. As a result, the overall tensile stresses in the actuator are reduced, and the actuator displacement is improved.