A large-stroke deformable mirror by gear shaped IPMC design

Ionic polymer-metal composite (IPMC) is a promising electro-actuated polymer which can be used in MEMS devices because of large deformation with low applied voltage. We propose a convenient grey box model based on known mechanical properties of metal and Nafion^® including Young´s modulus and Poisson´s ratio. 3D structural solid element type (solid 45 in Ansys^®) is used in finite element method (FEM). We separate the Nafion^® into two virtual layers, one is expansive and another is contractive caused by opposite constant surface force, or pressure, on each surface of elements. By simulations, the relation of surface force with tip displacement could be derived. After the experiment of voltage to tip displacement, we can determine the relation between voltage and surface force. Therefore, the deformation for different pattern or shapes can be predicted more easily. Finally, the gear shaped IPMC actuator is designed as a deformable mirror by simulation and the experiment result is presented.