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ABSTRACT: Relatively independent of the physical dimensions of
micro-actuators based on shape memory alloys (SMA), the reported
frequency response typically is capped at a few tens of Hz. The slow
response agrees well with that of the rotating micro-actuators
fabricated in this work. On the other hand, based on heat transfer
analyses, a theoretical response time of the order of a few
milli-seconds should be possible for scaled microactuators, thus
implying a frequency performance of at least a few hundred Hz. Therefore
it is concluded that the response of SMA micro-actuators may not be
limited by heat transfer, but by the slow rate of phase transformation
between the austenitic and the martensitic phases. This is consistent
with the slow phase growth rate of about 0.3 μm/s observed using
in-situ transmission electron microscopy
Micro Electro Mechanical Systems, 2000. MEMS 2000. The Thirteenth Annual International Conference on; 02/2000
