SBIR Phase II: Shear Stress Sensor Based on Optical Micro-Spring Technology

这个小企业创新研究（SBIR）第二阶段项目的目的是在thedelection壁剪切应力传感器的基础上微光学谐振器。该传感器的核心元件，微光学应力计（MOSG），由一个微光学球面谐振器和光纤，可调谐激光耦合进入和出球。通过监测作为球体变形函数的谐振器光谱的偏移，可以在谐振器的微小变形（1 nm）的情况下测量超过四个数量级的力。这种能力允许aMOSG被结合在剪切应力传感器内，其中与流体接触的浮动元件的运动是最小的。在第一阶段中，制作了传感器的试验板版本，并在两个平行板之间的模型流中进行了成功测试，其中测量结果与计算预测非常一致。第二阶段的研究将集中在通过提高测量速率、灵敏度和动态范围，沿着降低振动敏感性和提高鲁棒性来推进该技术。传感器原型将在高剪切工业混合器上进行测试，目的是为过程混合市场实现商业化。该项目更广泛的影响/商业潜力将包括促进对流动边界层中发生的基本过程的理解。对于非牛顿流体或其他流变复杂的流体，壁面剪切应力不能可靠地计算，或者测量，特别是对于不透明的流体。所提出的传感器填补了流体动力学，空气动力学和医学研究领域的剪切应力测量的需要。预计最大的影响将出现在化工和制药行业，这些行业无法扩展和预测加工设备的性能。壁面剪切应力的知识将提供改进过程控制、产品质量和生产量的方法，所述产品包括药物和其它医药产品、食品、油漆、油墨和染料、化妆品和许多其它产品。

This Small Business Innovation Research (SBIR) Phase II project is aimed at thedevelopment of a wall shear stress sensor based on micro-optical resonators. The core element of the sensor, the micro-optical stress gauge (MOSG), consists of a micro-optical spherical resonator and optical fibers through which tunable laser light is coupled into and out of the sphere. By monitoring shifts of the resonator spectrum, that are a function of the deformation of the sphere, forces can be measured over more than four orders of magnitude with minute deformation of the resonator ( 1 nm). This capability allows aMOSG to be incorporated within a shear stress sensor in which the motion of a floating element in contact with the fluid is minimal. In Phase I, a breadboard version of the sensor was fabricated and successfully tested in a model flow between two parallel plates, where measurements were in close agreement with computational predictions. Phase II research will focus on advancing the technology by improving measurement rate, sensitivity, and dynamic range, along with decreasing vibration susceptibility, andimproving robustness. Sensor prototypes will be tested on high shear industrial mixers with the aim of commercialization for the process mixing market.The broader impact/commercial potential of this project will include the advancement of the understanding of the fundamental processes occurring in boundary layers of flows. For non-Newtonian or otherwise rheologically complex fluids, wall shear stress cannot be reliably calculated or, especially for non-transparent flows, measured. The proposed sensor fills a need for shear stress measurement in the fields of fluid dynamics, aerodynamics and medical research. The largest impact is expected to be in the chemical and pharmaceutical industries that are suffering from an inability to scale and predict processing equipment performance. Knowledge of wall shear stress will provide means to improve process control, quality and throughput of products including drugs and other pharmaceutical products, foods, paints, inks and dyes, cosmetics, and many others.