Design, control, and application of piezoelectric actuator: External-sensing and self-sensing actuator

Abstract

Piezoelectric actuators have received increasing attention in recent years, along with the emergence of new technologies, which require an unprecedented precision of position control of the order of sub-micrometer. The application of piezoelectric actuators is further fuelled by the trend of miniaturization in applied research and in the industry nowadays. The design and control of piezoelectric actuators, however, call for a special approach that has to take care of the unique properties of piezoelectric materials, as well as the applications to which the actuators are to be used, so as to meet the requirements. A development of piezoelectric actuators is presented in this thesis with a mechatronic approach, combining the mechanical, electrical, and control engineering. Special mechanisms and control techniques are implemented so as to meet the requirements of the applications. Firstly, an external-sensing actuation (ESA) is discussed, with the application in intra-cytoplasmic sperm injection. ESA is essentially the usual technique where a separate, independent sensor is installed to allow the implementation of feedback control. Secondly, a self-sensing actuation (SSA) is discussed, with the application in a microdispensing system. SSA implements a single piezoelectric component to function as both an actuator and a sensor, making full advantage of the properties of the piezoelectric components.