An Array of Miniature, conformal and Waterproof Optical Shear Stress Sensors for Naval and Marine Vehicle Applications

The development of an array of miniature optical shear stress sensors in a conformal, waterproof package is critical to the achievements of the design of agile and maneuvering submarines and other underwater vehicles. The objective of this researchproject is to continue the development of optical shear stress sensors using micro-optical diffractive optic elements, which will provide accurate, in-situ measurement of the wall shear stress at a number of points over a submerged vehicle. In Phase I,feasibility of novel micro-optical shear stress sensors was demonstrated. The new sensors provide unambiguous wall shear data both for attached and reversed flows. A relatively large number of sensors can be affixed to the outside of submerged vehicles andsimultaneous data can be acquired using on board data management and recording system. Phase II will pursue advanced development of fabrication of multiple sensor packages. The sensor designs will be optimized, fabricated and integrated into an array ofsensors. Application of micro-machining and automated aligning procedures in Phase II options and Phase III will result in efficient and reliable fabrication of larger arrays of sensors at lower per unit cost. Commercial application of single and multiple sensor configurations has already been identified in the areas of general fluid mechanics and aerodynamic research including the on going Navy-supported drag reduction efforts. The miniature sensors have alsoa large potential market in the medical field. The completed device could be used for In Vivo measurement of shear stress in arteries.