Ultrahigh humidity sensitivity of graphene oxide

TLDR

Humidity sensors are widely used but suffer from low sensitivity, slow response and recovery, and limited humidity ranges. The study aims to develop a microscale capacitive humidity sensor using graphene oxide films. The sensor is fabricated from graphene oxide films. The graphene oxide sensor achieves a sensitivity of up to 37,800 %, more than tenfold higher than conventional sensors, and shows faster response and recovery times, making it ideal for ultrahigh‑sensitivity humidity sensing.

Abstract

Humidity sensors have been extensively used in various fields, and numerous problems are encountered when using humidity sensors, including low sensitivity, long response and recovery times, and narrow humidity detection ranges. Using graphene oxide (G-O) films as humidity sensing materials, we fabricate here a microscale capacitive humidity sensor. Compared with conventional capacitive humidity sensors, the G-O based humidity sensor has a sensitivity of up to 37800% which is more than 10 times higher than that of the best one among conventional sensors at 15%-95% relative humidity. Moreover, our humidity sensor shows a fast response time (less than 1/4 of that of the conventional one) and recovery time (less than 1/2 of that of the conventional one). Therefore, G-O appears to be an ideal material for constructing humidity sensors with ultrahigh sensitivity for widespread applications.