High‐Sensitivity and Low‐Hysteresis GONH2/Mesoporous SiO2 Nanosphere‐Fabric‐Based Humidity Sensor for Respiratory Monitoring and Noncontact Sensing

Abstract Flexible humidity sensor, a promising device for monitoring humidity, is widely used for patients’ respiratory analysis due to its portability and cost‐effectiveness. However, through intrinsic rigid nature of traditional flexible substrate such as polymer and paper, the fiber‐based device exhibits great application potential in wearable platform. In this work, a fabric humidity sensor based on diamine‐decorated graphene oxide/mesoporous silica nanospheres (GONH 2 /mSiO 2 ) is designed via screen printing. The decoration of diamine is introduced to improve the hydrophilic properties of GO, and the mesoporous structure of mSiO 2 is employed to adjust the adsorption and desorption of water molecules. As a result, the fabric humidity sensor exhibits fast response (≈12.6 s), high sensitivity (14.8 MΩ/% relative humidity (RH)), and low hysteresis (2.71% RH) at the humidity interval from 23% to 97% RH. Owing to the GONH 2 /mSiO 2 composite materials screen‐printed on the medical mask, the fabric humidity sensor can delicately detect respiratory rates, mouth and nose breathing, as well as coughing. Moreover, the GONH 2 /mSiO 2 humidity sensor is applied for noncontact sensation (such as the detection of fingertip approaching). These properties allow the sensor to serve as excellent wearable electronics for real‐time and successive human health detecting.