We report on the development of a thermally isolated bimorph structure based on a Ni|Si pair. A 1-mm-long beam of the bimorph was thermally isolated by a polyimide comb from the rest of the Si structure. The Si and Ni layers of the bimorph were 20 µm thick. This geometry enabled us to generate the bending displacement (the stroke) of the free end of the bimorph up to 100 µm at about 100°C with a generated force of about 15 mN. Electrical power consumption for the 100°C working point was lower than 0.2 W and the response time was 0.5 s. This design entitles further miniaturization of micro-electromechanical systems (MEMSs) such as commercial microvalve structures and sensors. The principles of design and experimental results of temperature distribution for the bimorph are presented and discussed.
Japanese Journal of Applied Physics: Part 1: Regular Papers, Short Notes and Review Papers,
Vol. 42, no. 7A (Jul 2003), pp. 4464-4468