Fabric-based hydrophobic humidity sensors for measuring human insensible sweat rate

Sweat monitoring can reflect human health status, and insensible sweat is crucial for assessing skin barrier functions and physiological status. The development of a flexible, breathable, and insensible sweat rate sensor is still a challenge. Here we prepared a fabric-based humidity sensor for human insensible sweat rate monitoring. In which the CS/PVA/CNP composite material has a significant response to changes in humidity, the humidity-sensitive material and interdigital electrodes are encapsulated in the middle of two layers of hydrophobic fabrics, which effectively avoids the influence of external water on the sensor; and it is also breathable, ensures the wearing comfort. The sensor is integrated with wireless communication and powering module to monitor the insensible sweat rate at different body locations continuously. Human testing demonstrated the feasibility of the system to assess the insensible sweat rate of the body under different exercise conditions. Our sensor provides a low-cost device platform that offers new ideas for research in personalized medicine and smart clothing.