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Proceedings Paper

Microwave-driven smart material actuator
Author(s): Sang H. Choi; Sang-Hyon Chu; Mia Kwak; Andrew D. Cutler
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Paper Abstract

NASA's Next Generation Space Telescope (NGST) has a large deployable, fragmented optical surface (>= 8 m in diameter) that requires autonomous correction of deployment misalignments and thermal effects. Its high and stringent resolution requirement imposes a great deal of challenge for optical correction. The threshold value for optical correction is dictated by (lambda) /20 (30 nm for NGST optics). Control of an adaptive optics array consisting of a large number of optical elements and smart material actuators is so complex that power distribution for activation and control of actuators must be done by other than hard-wired circuitry. The concept of microwave-driven smart actuators is envisioned as the best option to alleviate the complexity associated with hard-wiring. A microwave-driven actuator was studied to realize such a concept for future applications. Piezoelectric material was used as an actuator that shows dimensional change with high electric field. The actuators were coupled with microwave rectenna and tested to correlate the coupling effect of electromagnetic wave. In experiments, a 3 X 3 rectenna patch array generated more than 50 volts which is a threshold voltage for 30-nm displacement of a single piezoelectric material. Overall, the test results indicate that the microwave-driven actuator concept can be adopted for NGST applications.

Paper Details

Date Published: 9 June 1999
PDF: 11 pages
Proc. SPIE 3668, Smart Structures and Materials 1999: Smart Structures and Integrated Systems, (9 June 1999); doi: 10.1117/12.350762
Show Author Affiliations
Sang H. Choi, NASA Langley Research Ctr. (United States)
Sang-Hyon Chu, NASA Langley Research Ctr. (United States)
Mia Kwak, George Washington Univ. (United States)
Andrew D. Cutler, George Washington Univ. (United States)

Published in SPIE Proceedings Vol. 3668:
Smart Structures and Materials 1999: Smart Structures and Integrated Systems
Norman M. Wereley, Editor(s)

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