Abstract
This paper reports a novel shear stress sensor utilizing flexible membrane and double SU-8 resist structures as a Fabry-Perot interferometer. Through UV lithography on thick resist, the surface roughness of the reflection surface better than 7 nm (Ra value trough 10*10 μn 2 area), suitable for optical application. A single mode optical fiber was employed for detecting the displacement of the floating element representing the shear stress force on the flexible membrane. Test has been successfully carried out and demonstrated a detection possibility of 10-nm-displacement, representing a minimum detectable wall shear stress of 0.065 Pa from simulation, comparable to its counterparts with resolutions from 0.1-1 Pa.