Graphene Oxide Based Sensor with Differential Structure for Humidity and Temperature Detection

A GO (graphene oxide)-based sensor with differential structure was designed to detect both humidity and temperature. Two identical units have been fabricated with patterned gold electrodes on which a layer of GO was deposited by drop-casting or spraying coating method. One unit was then covered by a layer of PDMS to modify its response to the temperature and humidity. Using this differential structure, the sensor shows great linearity in a temperature range from 20 degrees C to 60 degrees C and a humidity range from RH25% to RH95%. The humidity response of the two units varied for three orders of magnitude under the same temperature, which indicates a good sensitivity of the device. We have also found that the spraycoated sensor has a relatively short response and recovery times than the drop-casted one.