Piezohydraulic Actuation for Next Generation Microjet Flow Control

This paper describes the development of a new piezohydraulic actuator for integration into a microjet flow control device. The actuator utilizes a lead zirconate titanate (PZT) stack actuator and a hydraulic amplification design to achieve relatively large displacements required to control flow through a microjet. Displacement amplification of 81 times the stack actuator displacement was achieved using a dual-diaphragm design that seals the fluid within the device. The nonlinear field-coupled structural dynamics and fluid behavior of the actuator is predicted using a system dynamic model and compared with experimental results. It is shown that minor loop hysteresis of the piezoelectric stack actuator and nonlinear deformation of the diaphragm play an important role in the piezohydraulic displacement amplification.