Thermo-pneumatically actuated, membrane-based micro-mirror devices

Abstract

A novel design for thermo-pneumatically actuated, membrane-based micro-mirror devices, using an elastomer membrane fabricated in a spin-coating process on a dry-etched silicon substrate, is presented. The silicon mirror devices are etched from the substrate and fixed to the highly elastic 50 µm thick membrane and actuated by thermo-pneumatic pressure. This pressure is generated by a micro-hotplate bonded to the backside of the silicon substrate. Such devices provide strokes from 0 to 80 µm and tilting angles in the range from 0° to 13°, relative to the substrate surface. Thermo-pneumatic actuation achieves large angle and stroke deflection, making this approach suitable for a large array of applications. Tilting mirrors, piston mirrors as well as mirror arrays have been realized using this technology.