A microfabricated floating-element shear stress sensor using wafer-bonding technology

A microfabricated floating-element (120 mu m*140 mu m*5 mu m) liquid shear stress sensor has been developed using wafer-bonding technology. The sensor has been designed for high shear stresses (1-100 kPa) and high-pressure environments (up to 6600 psi) and utilizes a piezoresistive transduction scheme. Analytical and finite-element method (FEM) modeling have been performed to predict the sensor response. The sensor has been tested for both its mechanical integrity in high-pressure environments and its output response in the controlled environment of a cone and plate viscometer. The processing steps in the fabrication of the sensor, the analytical and FEM modeling, the experimental procedures, and the results of the experiments are described. >