Patent Number: 7,787,171

Title: Human-readable, bi-state environmental sensors based on micro-mechanical membranes

Abstract: An environmental sensing device includes an interferometric modulator which permanently actuates, in a visually-detectable manner, in response to being exposed to a predetermined environmental threshold or condition. The device can include a reactive layer, coating, or proof mass disposed on a movable member of the interferometric modulator. The reactive layer, coating, or proof mass can expand, contract, bend, or otherwise move when exposed to a predefined chemical, level of humidity, temperature threshold, type of radiation, and/or level of mechanical shock, causing the interferometric modulator to collapse and permanently indicate such exposure.

Inventors: Webster; James Randolph (San Jose, CA)

Assignee: QUALCOMM MEMS Technologies, Inc.

International Classification: G02B 26/00 (20060101)

Expiration Date: 8/31/12018