Active Membrane Using Electrostructure Graft Elastomer for Deployable and Lightweight Mirrors

An important requirement enabling future space missions is the availability of very large, deployed, re-configurable apertures for high-resolution imaging. Membrane-based architectures have the potential for very low aerial densities, which will enable large aperture space telescopes. Two major requirements for considering large apertures are: 1) a high degree of surface control coupled with a low-mass deployable capability and 2) an optical quality membrane mirror technology. Current state-of-the-art deployable aperture technologies have significant limitations in their ability to correct the surface figure following deployment. In this paper, a controlled deformation of silicon membrane mirrors using electroactive polymer has been demonstrated to overcome these limitations. We have designed, modeled, and fabricated Electrostrictive Graft Elastomer (G-elastomer)-based bi-layer membranes. The bi-layer mirror membranes maintain a good working condition after thermal cyclic tests, performed at temperatures between −50 °C and 150 °C. G-elastomer provides means to drive and control the deflection and curvature of reflective membranes. Several G-elastomer-based bi-layer structures have been optically characterized. This concept can be scaled to a deployable ultra-large mirror with a self-reconfiguration capability.