Journal
IEEE SENSORS JOURNAL
Volume 3, Issue 6, Pages 812-817Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/JSEN.2003.820364
Keywords
Fabry-Perot interferometer; fiber-optic sensor; flexible membrane; floating element; nano-displacement; polymer microelectromechanical systems (MEMS); shear stress sensing
Ask authors/readers for more resources
This paper reports a novel optical fiber-based microshear stress sensor utilizing a flexible membrane and double SU-8 resist structures as a moving micro-mirror, together with an optical fiber as a micro-Fabry-Perot interferometer. This sensor can be employed in air or liquid environments with high sensitivity because of its waterproof design. Through UV lithography processes on thick SU-8 resist, the roughness of the reflection surface has approached 7 nm (Ra value), suitable for optical applications. A single-mode optical fiber is employed for detecting the displacement of the floating element induced by shear stress. Tests have been carried out successfully and a detection possibility of 10 nm-displacement of the floating element and a displacement sensitivity of 0.128 nm/nm (spectrum shift/floating element displacement) has been demonstrated. The temperature coefficient of this fiber-optic sensor has been characterized to be 3.4 nm/K linearly from 25 to 48 degreesC. Fluid tests have also been performed by placing the sensor inside the inner wall of a precisely machined rectangular channel and the result shows a sensitivity of 0.4 nm/ml/min (spectrum shift/flow rate), corresponding to a shear stress resolution of 0.65 Pa/nm (shear stress/ spectrum shift). The minimum detectable shear stress is thereby estimated as 0.065 Pa from the reading resolution of the spectrometer of 0.1 mn, comparable to its counterparts with resolutions from 0.1-1 Pa.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available