Development of a Mesoscale Solid-State Servo-Hydraulic Actuator

This report is a compilation of work related to the development of a high-pressure high flow rate piezoelectric micropump. Such a pump would be at the heart of a small servohydraulic actuation system. The objective of this project was to determine the feasibility of such an actuation system. One of the biggest challenges facing small-scale servohydraulic systems is the development of a high performance micro pumping device. To achieve the final result: a) detailed mathematical models of the micropump as well as the micro - servohydraulic system were constructed; b) a micropump was designed, taking into account all the relevant limitations related to the current state-of-the-art microfabrication techniques; and c) a micropump was built and tested. The final micropump was a seven-layer microfabricated device consisting of 4 silicon and 3 glass layers. The silicon layers were fabricated using Deep Reactive Ion Etching (DRIE). The glass layers were made using conventional diamond drilling. The final device was assembled using a sequence of Silicon-silicon fusion bonds and silicon-glass anodic bonds. The maximum performance attained from this device was - a maximum flow rate of 2700 microliters/min and a maximum differential pressure of 450kPa at a piston drive frequency of 12.5kHz.