Noncontact sensing for water area scanning identification based on Ho2O3/GO humidity sensor

With the advent of the era of intelligent perception and artificial intelligence, higher requirements on the response/recovery speed of humidity sensitive materials and the expansion of new applications of humidity sensors have been put forward. In this study, Ho2O3/GO composites were obtained by ultrasonic stirring of the GO solution with the synthesized Ho2O3 material. Benefiting from the presence of adsorbed hydroxyl oxygen on the surface and the regular arrangement of the nanosheets, the humidity response of Ho2O3/GO sensor has nearly doubled from 1102 to 2136, and the recovery time was reduced by more than half from 6 s to 1 s. Based on excellent humidity sensitive properties, the sensor was used for non-contact scanning to identify water zones of different shapes, thus presenting information on the distribution of water beneath the sensor. This research opens up further possibilities for the expansion of humidity sensors in emerging applications such as smart sensing.