Design and fabrication of a piezoelectric stack actuator for use in a needle-free jet injector

Abstract

This thesis presents the design of a piezoelectric ceramic stack actuator for use with needle-free jet injection (NFJI) devices. While NFJI devices have been in use for over 60 years only recently have they been electronically actuated which allows for precise control of jet velocity, penetration depth, and injection volume. Most NFJI devices have been designed for fluids with a similar viscosity to water. Here we design an actuator for use with high viscosity fluids and non-newtonian fluids. The piezoelectric stack actuator presented in this work has been designed to deliver injection volumes of up to 30 microliters while pressurizing the fluid to over 40 MPa in order to achieve the necessary fluid velocities for injection. We have further presented all the methods used in order to fabricate functional lead zirconate titanate (PZT) piezoelectric ceramic discs. These discs are the basic building blocks for assembling a full stack actuator for NFJI.