Articles written in Sadhana
Volume 34 Issue 4 August 2009 pp 615-623
This paper presents a novel MOEMS (Micro Opto Electromechanical Systems) pressure sensor suitable for localized precision measurements in high temperature environments. The sensor is based on a micromachined Fabry–Perot device (MFPD) that uses a thin ﬁlm microcantilever beam as the top mirror and a silicon substrate as the bottom mirror of the optical microcavity. The major effect that the viscosity and density of the air surrounding the MFPD have on the viscous damping provides the mechanism for the detection of the pressure. A major advantage of this conﬁguration is that there is no need for a sealed microcavity since the air is trapped by the viscous damping effects. The sensor has been tested up to 90 psi and pressure sensitivities of about 0·04%/psi with a MFPD sensor with a resonant frequency of about 46·7 kHz have been measured.