基于柔性MEMS皮肤技术温度传感器阵列的研究

采用MEMS皮肤技术,在聚酰亚胺柔性衬底上成功研制出8×8阵列铂薄膜热敏电阻温度传感器。实验采用热氧化硅片为机械载体,以便于旋涂液态聚酰亚胺柔性衬底上器件的加工。最后用湿法腐蚀方法将柔性器件从载体上释放下来。试验表明聚酰亚胺衬底上的铂薄膜热敏电阻与温度的变化具有良好的线性,其电阻温度系数达0.0023/℃。与固态聚酰亚胺膜衬底相比,采用旋涂液态聚酰亚胺解决了制备中遇到的两大主要困难:其一,消除了涂聚酰亚胺衬底与载体界面之间的气泡,聚酰亚胺衬底表面能保持良好平整度;其二,制备过程中由于热循环而使柔性衬底产生的热膨胀明显减小。这种柔性温度传感器阵列易贴于高曲率物体表面以探测小面积温度场分布。

A temperature sensor array based on flexible MEMS skin technology

A 8×8 array platinum film resistor temperature sensor on polyimide flexible substrate was successfully fabricated based on MEMS skin technology. The flexible polyimide substrate were formed by spin-coating liquid polyimide on a thermally oxidized silicon wafer. The wafer was used as a mechanical carrier for the flexible substrate during device fabrication. The finished flexible devices were finally separated from the carrier by wet etching. The test results show that the platinum film resistor temperature sensors on polyimide substrates exhibit excellent linearity and the temperature coefficient of resistance is close to 0.0023/℃. The spin-coated liquid polyimide solves two major problems comparing with the solid polyimide sheets as a flexible substrate. First, flatness of the flexible substrate is maintained with no air bubbles between the interface of ployimide and silicon. Second,the thermal expansion of the flexible substrates during the fabrication process due to thermal cycling is reduced greatly. The flexible skin with a temperature sensor array can be easily attached on a highly curved surface to detect temperature distribution inside a small area.