<title>Design of piezoelectric motors using topology optimization</title>

Abstract

Piezoelectric motors consist essentially of a coupling structure actuated by two or more piezoceramics excited with different phases. The actuated piezoceramics deform the coupling structure which moves due to friction over a fixed structure, called stator. The motor performance is related to the displacement generated by the motor in the moving direction and clamping force between the coupling structure and stator. Both quantities depend on the distribution of flexibility and stiffness in the coupling structure domain, which is related to coupling structure topology. By designing other types of coupling structures connected to the piezoceramics, novel types of piezoelectric motors with enhanced performance can be obtained. In this work, topology optimization is applied to design piezoelectric motors. Topology optimization is a general computer design method applied to design optimal structural topology that improves a specified objective function in according to some constraints. The optimization problem is posed as the design of a flexible structure coupled to the piezoceramics that maximizes the output displacement and clamping force in a specified point of the domain and direction. The design of a quasi-static inchworm-type piezoelectric motor is presented to illustrate the implementation of the method.