基于纳米森林的电容式湿度传感器

Capacitive Humidity Sensor Based on Nano-Forest

提出了一种基于纳米森林的电容式湿度传感器。该湿度传感器利用等离子体技术制备的纳米森林作为湿度敏感层,湿度敏感范围为30%RH^90%RH,且在大于60%RH的湿度范围内灵敏度达到1.87 pF/%RH,同时响应和恢复时间分别约为3.2 s和6 s。当传感器置于湿度环境中时,吸收在纳米森林表面并凝结在表面孔隙中的水分子导致纳米森林介电常数发生变化,进而引起电容值的改变。通过与聚酰亚胺湿度传感器对比,证明基于纳米森林结构的湿度传感器具有更加优异的湿敏性能。此外,该传感器还可作为湿度触发的非接触式开关,有望应用于电梯按键等公共设备上,用于抑制细菌传播。

A capacitive humidity sensor based on nano-forest was proposed.The nano-forest prepared by plasma technology was used as humidity-sensitive layer for the humidity sensor.The humidity sensitive range is 30%RH-90%RH,and the sensitivity reaches 1.87 pF/%RH in the humidity range of above 60%RH,the response time and recovery time are about 3.2 s and 6 s,respectively.When the sensor is in a humid environment,the water molecules absorbed on the nano-forest surface and condensed in the surface pores cause the change of dielectric constant of the nano-forest,thereby leading to the change of the capacitance value.Compared with the polyimide humidity sensor,the humidity sensor based on nano-forest has more excellent humidity sensitive performance.In addition,the sensor can also be used as a non-contact switch triggered by humidity,which can be used in public equipment,such as elevator buttons and so on,to suppress the spread of bacteria.