Paper-based device provides low-power, long-term method for analyzing sweat

Researchers have constructed a paper-based device as a model of wearables that can collect, transport and analyze sweat in next-generation wearable technology. Using a process known as capillary action, akin to water transport in plants, the device uses evaporation to wick fluid that mimics the features of human sweat to a sensor for up to 10 days or longer.

source https://www.sciencedaily.com/releases/2020/06/200609111102.htm