A novel MEMS pressure sensor fabricated on an optical fiber

We describe the fabrication, and initial testing of a novel optically interrogated, microelectromechanical system (MEMS) pressure sensor in which the entire MEMS structure is fabricated directly on an optical fiber. A new micromachining process for use on a flat fiber end face that includes photolithographic patterning, wet etching of a cavity, and anodic bonding of a silicon diaphragm is utilized. We have employed both 200- and 400-mum-diameter multimode optical fibers. A pressure sensor fabricated on an optical fiber has been tested displaying an approximately linear response to static pressure (0-80 psi). This sensor is expected to find application in situations where small size is advantageous and where dense arrays may be useful.