Development of a Miniature Shear Sensor for Direct Comparison of Skin-Friction Drags

摘要

This paper presents the design, fabrication, and characterization of a silicon-micromachined mechanical sensor that directly compares the wall shears of two different surfaces in a liquid flow. The 27 mm mm sensor contains two 10 mm mm mm plates suspended to displace in proportion to the shear force on each surface. The monolithic sensor designed to compare skin-friction drag on two different surfaces consists of two floating plates, each suspended from a frame by identical flexure beams etched out of a 0.2-mm-thick silicon wafer. Design of the sensor is assisted by finite-element analysis to ensure adequate structural characteristics in the intended flows and validated by experimental characterization. The fabrication process is presented in detail, including how to form millimeter-long beams with a uniform cross section in micrometers and release the centimeter-scale plates suspended by the delicate beams. This paper provides a guidance to develop a miniature shear comparator using silicon microfabrication technologies. [2014-0258]