A Highly Sensitive Humidity Sensor Based On Nanoforests

Abstract

In this work, a highly sensitive humidity sensor using superhydrophilic nanoforests as its humidity sensitive material is proposed. The humidity sensor is composed of a capacitor with nanoforests, a thermistor, a micro-heater and a reference capacitor. In a relative humidity range of 10-90%RH, sensitivity of the nanoforest-based sensor is 15 times higher than that of a polyimide-based sensor with the same structures. Meanwhile, integration of a micro-heater into the humidity sensor can reduce the humidity response time by 10 s, and the use of a thermistor and a reference capacitor can help to obtain higher accuracy. In addition, the fabrication process of this sensor is simple and compatible with COMS processes, thus such a humidity sensor is suitable for batch production and has potential to replace existing sensors with low performance.