Vertical electrostatically 90° turning flaps for reflective MEMS display

A new kind of MEMS reflective display is being developed having high contrast and reflectivity, better than on printed paper. The system is based on novel vertical flaps, which can be electrostatically turned by 90° to horizontal position. After fabrication, the poly-silicon flaps are vertical to the wafer surface and on the top suspended by torsion beams. In this state the pixel is black, incoming ambient light passes by the flaps and is absorbed by an underlying absorptive layer. When the flaps are turned to horizontal position light is reflected back and the pixel gets white. A self-aligning four masks bulk microfabrication process is employed, which uses poly-silicon filling of high aspect-ratio cavities. Parylene was also employed as flap material. Thanks to auto stress-compensation the flaps are not deformed due to intrinsic stresses. Low actuation voltages down to 20V can be achieved

Published in:
Proceedings of SPIE, 79300H
Presented at:
Photonics West 2011, San Francisco, USA, January 22-27, 2011
Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa

 Record created 2011-11-11, last modified 2018-03-17

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