Experimental and Numerical Characterization of Multi-Actuated Piezoelectric Device Designs Using Topology Optimization

摘要

Multi-actuators piezoelectric devices consist of a multi-flexible structure actuated by two or more piezoceramic portions, whose differing output displacements and forces are tailored according to the excitation properties of the piezoceramic materials and the desired working locations and directions of movement. Such devices have a wide range of application in performing biological cell manipulation, for microsurgery, and in nanotechnology equipment, and the like. However, the design of multi-flexible structures is a highly complex task since the devices have many degrees of freedom and, employ a variety of piezoceramics, but must carefully tune the movement coupling among the device parts to prevent motion in undesirable directions. In prior research, topology optimization techniques have been applied to the design of devices having minimum movement coupling among the piezoceramic parts, and in this work a number of these devices were manufactured and experimentally analyzed to validate the results of the topology optimization. X-Y nanopositioners consisting of two piezoceramic portions were addressed and designs considering low and high degrees of coupling between desired and undesirable displacements were investigated to evaluate the performance of the design method. Prototypes were manufactured in aluminum using a wire EDM process, and bonded to piezoceramics (PZT5A) polarized in the thickness direction and working in d31 mode. Finite element simulations were carried out using the commercial ANSYS software application. Experimental analyses were conducted using laser interferometry to measure displacement, while considering a quasi-static excitation. The coupling between the X-Y movements was measured and compared with FEM results, which showed that the coupling requirements were adequately achieved.