Focus tunable mirrors made by ionic polymer-metal composite

In order to meet current requirement, electronic products are made smaller and thinner. We used focus tunable mirrors in optical systems to make camera modules thinner and lighter in electronic products. An Ionic-Polymer Metal Composite (IPMC) plays a critical role in our design. It has good bending feature and can be driven by low voltage (usually less than 5 volts). Other technologies such as liquid lenses, MEMS deformable mirrors, and liquid crystal lens, all need higher voltage to reach similar optical focusing power. After fabrication of IPMC, we used PDMS on one surface to improve the surface roughness before reflective metal is deposited. Key characteristics of IPMC focus tunable mirror are demonstrated in this paper. By coating a silver layer on the IPMC surface, the reflection is up to 90%. From simulation results, the zoom ratio of this module can be expected 1.8 times. Experimentally, the deformable mirror can be changed from flat to 65 diopters (m(-1)) by only 3 volts. In this paper, we demonstrated a reflective optical zoom module with three fixed mirrors and two deformable mirrors.