Measurement of Structural Loads Using a Novel MEMS Extrinsic Fabry–Perot Strain Sensor

Abstract

In this paper, microelectromechanical systems (MEMS) technology was used to fabricate a novel extrinsic fiber Fabry–Perot (EFFP) strain sensor; this fiber sensor is applied to measure load with higher precision for a small structure. The sensor cavity consists of two Fabry–Perot (FP) cavity mirrors that are processed by surface micromachining and then fused and spliced together by the silicon–glass anode bonding process. The initial cavity length can be strictly controlled, and the excellent parallelism of the two faces of the cavity results in a high interference fineness. Then, the anti-reflection coating process is applied to the sensor to improve the clarity of the interference signal with the cavity, with its wavelength working within the range of the C + L band. Next, the sensor placement is determined by the finite element software Nastran. Experimental results indicate that the sensor exhibits a good linear response (99.77%) to load changes and a high repeatability. Considering the strain transfer coefficient, the sensitivity for the tested structure load is as high as 35.6 pm/N. Due to the miniaturization, repeatability, and easy-to-batch production, the proposed sensor can be used as a reliable and practical force sensor.

Design and Development of a MOEMS Accelerometer Using SOI Technology

“…Furthermore, it uses an optical interrogation with an FPI. Other related studies have used MOEMS to measure pressure [ 16 , 20 , 28 ], strain [ 23 , 29 ], or in-plane motion [ 3 , 25 ]. However, some require a stable optical reference and no mechanical connection but still need open optical access paths to the moving target section [ 3 , 26 ].…”

Microdisplacement Measurement Based on F-P Etalon: Processing Method and Experiments

“…After being traditionally used in astronomy since the 1970s [ 1 ], it has been widely used in LIDAR instruments for environmental monitoring [ 2 ], laser technology [ 3 ], atmospheric optics [ 4 , 5 ], marine optics [ 6 ], gas analysis [ 7 ], length measurement, and angle metrology [ 8 ]. The F-P interferometric technology not only includes the F-P etalon but also other structures with F-P interference form such as the optical fibre F-P interferometer [ 9 , 10 ], MEMS F-P interferometer [ 11 , 12 ], and complex mixed F-P interferometric measurement [ 13 , 14 ] of multiple quantities of temperature, displacement, structural loads, electro-optic coefficients, twist/rotation, strain, and pressure [ 15 , 16 , 17 , 18 , 19 ].…”