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.

An electromagnetically-driven microfluidic platform with indirect-heating thermo-pneumatic valves

“…It is worth mentioning that thermo-pneumatic actuation scheme has been widely utilized in various MEMS devices [25][26][27] , because of the advantages such as simple device structure, simple actuation scheme, relatively low actuation voltage, and small footprint. However, since the temperature elevation resulting from heating may damage biological samples, this actuation scheme in general is incompatible with biomedical applications.…”

Novel components for tunable micro-optics

“…Membrane-based optics may be also expanded to cover a range of further tunable micro-optical elements, in particular pneumatically-actuated scan as well as tip-tilt micro-mirrors. [6,7] Tunable micro-lenses based on the concepts described above are of considerable value in compact optical systems with enhanced functionality and are being developed, for example, for use in endoscopic optical coherence tomography systems. [8] Numerous other technologies have become relevant for tunable microoptics in general, particularly silicon-based opto-thermal filters [9] and polymer structures with controlled swelling.…”

Optical Micromirror Actuation using Thermocapillary Effect in Microdroplets

“…For example, various micromirrors, made by MEMS fabrication, have been demonstrated. These mirrors are mostly actuated by using thermo-pneumatic [1], electrostatic [2] and temperature gradient [3] techniques. Many of them need complicated microfabrication processes, and contain beam structures, which may suffer degradation due to torsion or contact.…”