A new study by researchers from the Tokyo University of Science (TUS) demonstrates the use of "heat-transfer printing" to place a thin, flexible chloride ion sensor onto a textile substrate. Their work was published in the online journal ACS Sensors. 

A wearable chemical sensor that can detect the level of chloride ions in sweat has been created by researchers. The sensor may help diagnose heat stroke and dehydration early and may be placed on the outside surface of popular fabrics to prevent skin irritation and allergies. The sensor may be applied to fiber substrates using the heat-transfer printing process, which enables it to be integrated into textiles like T-shirts, wristbands, and insoles. Additionally, by moving the sensor to fiber substrates, it is possible to establish a solid electrical connection and avoid edge blur. To protect the user from allergic responses, the researchers carefully chose the materials and electrochemical processes.

Researchers’ conducted experiments using fake sweat to test the sensors precision in monitoring chloride ion concentration after it was created.  The range of chloride ion concentrations in human sweat showed a Nernst response and a linear correlation with the sensor. The findings were not affected by any additional ions or compounds commonly found in sweat.

Researchers tested the sensor on a volunteer who cycled for 30 minutes on a stationary bike while taking five-minute measurements of their sweat rate, blood chloride levels, and saliva osmolality. The suggested wearable sensor can correctly measure the quantity of chloride ions in sweat and wirelessly transmit data, making it useful for in-the-moment health monitoring. 

This study illustrates the possibility of employing wearable ion sensors for managing athlete training and developing personalized healthcare through real-time sweat biomarker monitoring.

 (Source:https://www.sciencedaily.com/releases/2023/07/230706124552.htm)