微管道内的剪应力传感器

Shear Stress Sensor in Micro-Channel

制作了一个微管道内的剪应力传感器,该传感器通过热传递的原理工作。采用硅微加工技术制作微管道,在玻璃上通过溅射方法形成钛铂合金热膜,最后将两者键合封装,形成埋置了热膜的封闭微管道。测量了热膜的电阻温度系数,确定了热膜处于不同输入功率下的过热比。对该剪应力传感器进行了方波实验,确定其工作在不同过热比下的时间常数。对传感器进行实验标定,得到不同进出口压差下,微管道内的壁面剪应力大小。

A shear stress sensor based on heat transfer principle has been developed in a micro channel. A silicon wafer with micro channels and a pyrex glass with hot films have been bonded to form this sensor. The temperature coefficient of resistance is measured and over heat ratios with various input powers are determined. Square waves are superimposed on a constant bias current to determine the time constants under diversiform over heat ratios. Calibration has been conducted and shear stresses versus pressure difference have been tested.