Humidity Sensor Based on Two-Dimensional SnSe2/MWCNT Nanohybrids for the Online Monitoring of Human Respiration and a Touchless Positioning Interface

Herein, we report the significantly enhanced humidity responsiveness of resistive devices based on two-dimensional SnSe2/MWCNT nanohybrids. The multifunctional humidity sensor was exploited to establish a human–machine interface and for human interactive applications such as breath monitoring and sensing of the humidity of human skin for a touchless positioning interface. The sensor exhibited great potential owing to a high surface-to-volume ratio of SnSe2/MWCNT nanohybrids. The sensor has good linear response over a broad humidity range from 10–70% with fast response and recovery. The sensor shows the humidity responsivity of 0.148 in the humidity range of 10–70% and 0.063 for the humidity range of 75–95%. The maximum current sensitivity of 857% is achieved at 95% relative humidity for SnSe2/MWCNT nanohybrids, which is quite higher than the sensitivity obtained for pristine SnSe2 nanosheets. As a high-performance electronic device, the sensor has extremely low noise level and high recognition power for small humidity variations. The present finding advocates the huge development in humidity monitoring for biomedical, intelligent electronics, and industrial applications.