The objective of our Compact Hybrid Actuator Device (CHAD) program is to produce a novel, ultra-compact, high force actuator to meet the aggressive requirements for navigation, guidance and control of a compact missile as well as other military and commercial applications confronted with tight volume constraints. Our approach to this challenge uses the high power density of thin film shape memory alloys coupled with fluid rectification and commercial power electronics. Phase One of our program demonstrated the performance of critical technical elements in a non-compact form factor. NiTi films were reproducibly deposited and then fabricated into bubble actuators that demonstrated ≥ 100 Hz performance when forced convection heat transfer to a liquid was optimized. Increased efficiency in thermal activation was achieved through high Joule heating rates for short duty cycles; this allowed simplification of the power electronics. These technical elements were combined to produce a thin film SMA pump which ultimately demonstrated force outputs on the order of 250 N and average power densities on the order of 50 W/kg when operated at 100 Hz. The demonstrated performance shows great promise for applications requiring ultracompact form factors with high output force.

Date Published: 14 August 2003
PDF: 11 pages
Proc. SPIE 5054, Smart Structures and Materials 2003: Industrial and Commercial Applications of Smart Structures Technologies, (14 August 2003); doi: 10.1117/12.483889

Published in SPIE Proceedings Vol. 5054:
Smart Structures and Materials 2003: Industrial and Commercial Applications of Smart Structures Technologies
Eric H. Anderson, Editor(s)