1. Design and Characterization of Single-Layer Step-Bridge Structure for Out-of-Plane Thermal Actuator
- Author
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Wen-Chih Chen, Chih-Fan Hu, Weileun Fang, and Po-I Yeh
- Subjects
Microelectromechanical systems ,Bulk micromachining ,Materials science ,Bistability ,business.industry ,Mechanical Engineering ,Mechanical engineering ,Bending ,Structural engineering ,Vibration ,Surface micromachining ,Electrical and Electronic Engineering ,Actuator ,business ,Joule heating - Abstract
This paper presents the design and fabrication of a single-layer out-of-plane thermal actuator. The step-bridge structure design enables bending and then buckling of the actuator in the out-of-plane direction by Joule heating. Moreover, the moving direction of the actuator can be specified by the step structure. In summary, the step-bridge actuator design has the following five merits: (1) The load-deflection relation is easily tuned; (2) the bistable buckling behavior is prevented; (3) the unwanted vibration modes can be suppressed; (4) the delamination problem is prevented; and (5) the bridge structure is stiffer and more stable. The actuator and its application on a lens positioning stage have been implemented using p++ Si layer by bulk micromachining. It demonstrates that a typical actuator would move upward with an amplitude near 13 mum when driven at 54 mW.
- Published
- 2008
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