Effect of flexure hinge geometry on central deflection of piezo actuated diaphragm for micropump

Abstract

This paper discusses the effect of flexure hinge geometry on piezo actuated diaphragms for the micropump application. Use of flexure hinges in the diaphragm is one of the approaches to increase the diaphragm central deflection, selection of proper flexure hinges for out-of-plane application is important. COMSOL analysis is used to study the effect of flexure hinge geometry on the central deflection and stress distribution in the diaphragm. Rectangle hinge, circular cut-out hinge and corner fillet flexure hinges were chosen with a constant width of 1.5mm and 2mm length. In the present investigation, the central deflection of the diaphragm with different flexure hinges are studied and compared with a plane diaphragm with respect to actuating voltage. The simulation result shows that the maximum deflection is obtained from circular cut-out flexure diaphragm i.e. 9.35μm. Whereas stress distribution in circular flexure hinge diaphragm is more compared to rectangular flexure hinge diaphragm, which may lead to failure. Therefore rectangular flexure diaphragm has the advantage of minimum stress concentration with higher deflection compared to corner fillet and circular flexure. The deflection of rectangle flexure hinge diaphragm is 8.65μm which is 64% more compared to plane diaphragm. © 2017 IEEE.