| A direct, micromachined shear stress sensor using a Moiré amplification technique is presented in this dissertation. Shear stress or skin friction measurements are useful in aerodynamic, flow control and biomedical applications. Conventional approaches to shear stress measurements typically either indirect measurements or lack the spatial or temporal resolution required for time-resolved direct measurements. Indirect shear stress measurements infer shear stress using other flow quantity and require prior knowledge of the flow, which limits its usefulness during application. Micromachined floating element shear stress sensors offers the ability for direct, time-resolved, shear stress measurements.;This research uses an optical Moiré transduction technique for micromachined floating element device. Optical fibers are used to significantly reduce the packaging size and improve robustness over conventional microscope imaging systems. The prototype optical fiber bundle system developed in this research is demonstrated on an optical test-bed. In addition, the optical fiber bundle is demonstrated to work with a Moiré sensor for mean and dynamic shear stress measurements. |
