Fabrication of a thermopneumatic microactuator with a corrugated p plus silicon diaphragm

This paper presents a thermopneumatic microactuator consisting of a p + silicon diaphragm and a micro heater which are fabricated by micromaching. The thermopneumatic actuator of this paper is characterized by a corrugated diaphragm, which is more flexible than a Bat one. The diaphragm is driven by the air cavity pressure variation caused by ohmic heating and natural cooling. The diaphragm deflection is measured with a laser displacement meter. The static load-deflection characteristics of the corrugated and the Bat diaphragms to pneumatic pressure are obtained from experiments and compared with the calculated results. Also, the dynamic characteristics of the thermopneumatic actuators are investigated experimentally. The steady-state deflection of the actuator diaphragm is proportional to the voltage applied to the heater, and the mechanical sensitivity of the corrugated diaphragm and the Bat one are 6.25 and 2.22 mu m/V, respectively. The experimental result illustrates that the microactuator with the corrugated diaphragm is better than that with the flat one with respect to the performance. (C) 2000 Elsevier Science S.A. All rights reserved.