High frequency actuation of thin film NiTi

The frequency response of thin film nickel-titanium (NiTi) shape memory alloy (SMA) membrane in three fluid mediums (air, silicon oil, and de-ionized water) was investigated in the present paper. Operation was investigated at different power input and duty cycles. Results showed an operating frequency of 40 Hz could be achieved in de-ionized water with appropriate power input and duty cycles. Larger operating frequencies could be achieved by applying power over a short heating time to minimize the temperature rise in the surrounding fluid. Results demonstrated the extreme sensitivity of frequency to operating medium, power input, and duty cycle. That is, changing one of these parameters, the frequency response could be changed by an order of magnitude. (C) 2003 Elsevier B.V. All rights reserved.