Enhanced performance of a CMOS interdigital capacitive humidity sensor by graphene oxide

This paper presents a CMOS interdigital capacitive humidity sensor based on graphene oxide, and the sensitivity of this humidity sensor was improved significantly by using graphene oxide as sensing material. The passivation between the Al electrodes and the sensing material was used to ensure the reliability of the capacitive-type humidity sensor. The experimental results show that, compared with the sensor using polyimide as sensing material, the sensitivity of the sensor based on graphene oxide is 23 times larger, and the response time of such a sensor is also improved greatly.