Hybrid Optical/Micro-Mechanical Shear Stress Sensors

We propose to develop a new type of microfabricated sensor capable of measuring time-resolved shear stress inside turbulent boundary layers. Unlike existing micro-mechanical designs, the proposed sensor uses optical rather than electrical addressing. Optical addressing results in four important improvements: 1) More robust and rugged micro-mechanical sensors can be constructed by taking advantage of the high sensitivity of optical interferometry for the detection of small displacements, 2)optical addressing allows mutiple sensors to be placed on a single device, mitigating the effects of single sensor failure, 3) for research purposes,multiple sensors can easily be deployed over a test surface and suquentially addressed from outside the model, eliminating the need for electrical access behind the model, and 4) real-time full field analysis of shear stress will become possible by simultaneously addressing multiple sensors. The microfabricated sensor will be suitable for economical mass production and can be incorporated into both research and flight situations.