Pneumatically Actuated, Membrane-Based, Micro-Optical Devices

We discuss a novel fabrication technique for pneumatically actuated, membrane-based, micro-optical devices, including adaptive lenses and mirrors. These optical devices are actuated by a high elasticity membrane made of polydimethylsiloxane (PDMS), which is stretched over a structured silicon substrate. Pneumatic actuation not only allows direct modulation of micro-lens focal length from 0.5 to 18 mm, but also permits an extremely large range of micro-mirror tilt movement, up to 75 °, without the need for high-voltage actuation. Thus plano-convex and plano-concave lenses are realizable only by pressure adjustment. Tilting mirrors as well as piston mirrors can be easily fabricated together with lenses on the same silicon substrate.