Flexible humidity sensing and portable applications based on MoSe2 nanoflowers/copper tungstate nanoparticles

Abstract

This paper demonstrated the fabrication of molybdenum diselenide/copper tungstate (MoSe2/CuWO4) flexible humidity sensor. The humidity sensor was exposed to 0–97% RH levels at 20 °C to detect the humidity sensing properties and a list of flexible humidity testing experiments were measured as well. The MoSe2/CuWO4 film sensor showed ultrahigh response (C/C0 = 31982) and excellent repeatability. The different bending radius of the PET substrate had an influence on the response/recovery time of the MoSe2/CuWO4 film sensor. Furthermore, the mechanism of the MoSe2/CuWO4 film sensor was analyzed through complex impedance spectroscopy. The ability of monitoring human exhaled breath and finger approach provides great potential for the humidity sensor to be applied in various fields for humidity sensing. Meanwhile, the change of the sensor capacitance while human breathing, water droplets falling and finger approaching can be observed on the smartphone by connecting the humidity sensor to the portable device.