基于聚酰亚胺基底的热线式剪切应力传感器

Hot-Wire Shear Stress Sensors Based on the Polyimide Substrate

利用非硅微机械加工技术,制作了一种柔性热线式剪切应力微传感器。该传感器以聚酰亚胺膜为基底,可与被测曲面物体紧密贴合,具有较好的测量适应性和准确性。传感器采用线性度好、温度系数较高的铂金属制作敏感热线。为减少对被测流场的干扰且便于传感器的信号传输,传感器使用了背面引线结构。设计了恒温工作模式的传感器检测电路,并对电路的工作原理和参数设置进行了详细分析。对传感器进行了风洞实验,绘制得到剪切应力与输出电压的关系曲线。实验结果表明,设计制作的传感器及其电路可行。

A flexible hot-wire shear stress-sensor was fabricated with the non-silicon microma-chining technology.The sensor can be adapted to the curved surface with the polyimide as the base material,and has better measurement adaptability and accuracy.The sensitive hot wires of the sensor were made using the platinum with good linearity and high temperature coefficient.In order to reduce the interference of the flow field and facilitate the sensor signal transmission,the back lead structure was used in the sensor.The sensor detection circuit at constant-temperature mode was designed,and the operating principle and parameter setting of the circuit were analyzed.The experiment was made in the wind tunnel,the relationship curve of the shear stress and output voltage was obtained.The measurement results show that the design is feasible.