Ending the year on a high note. New in the journal Advanced Intelligent Systems, we show a simple yet elegant printed capacitive sweat rate sensor, which is very practical and validated with analytical modeling and on-body testing—A huge shout out to Mohammad Shafiqul Islam, Sangwon Cha, Md Farhad Hassan, Wenxin Cai, Tahsin Sejat Saniat, Cedar Rose Leach, for leading this amazing research. Looking forward to many new exciting wearables next year!

Paper title: Printed Wearable Sweat Rate Sensor for Continuous In Situ Perspiration Measurement

Abstract: Sweat rate measures key physiological states such as hydration levels and heat tolerance. Incorporating wearable technology with sweat rate sensors allows individuals to conveniently monitor their health, optimize workouts, and enhance occupational safety. However, challenges persist in such integration techniques, including intricate manufacturing, nonlinear responses to changes in sweat rates, and errors from the intermediate measurement of the distance sweat travels in the sensor. To address these issues, we present a comprehensive wearable platform that includes a fully printed, flexible sensor patch, readout electronics, and a mobile app for continuous, real-time monitoring of sweat rate. We fabricate a sensor patch with an area of 700 mm2 and a weight of 380 mg by utilizing direct 3D printing and scalable microfluidic fabrication. The microfluidic channels are 850μm wide and 164μm thick, with serpentine electrodes measuring sweat rate using capacitance. The custom readout electronics capture these changes in capacitance to accurately measure sweat rate, achieving a sensitivity of 0.01μLmin−1. The sensor’s performance is validated against analytical models, simulations, and on-body trials with commercial sensors. This cost-effective, flexible, and fully integrated sweat-sensing solution has significant potential in precision health.

Publication:

  1. Printed Wearable Sweat Rate Sensor for Continuous In Situ Perspiration Measurement Mohammad Shafiqul Islam, Sangwon Cha, Md Farhad Hassan, Wenxin Cai, Tahsin Sejat Saniat, Cedar Rose Leach, and Yasser Khan Advanced Intelligent Systems, 2024

    Sweat rate measures key physiological states such as hydration levels and heat tolerance. Incorporating wearable technology with sweat rate sensors allows individuals to conveniently monitor their health, optimize workouts, and enhance occupational safety. However, challenges persist in such integration techniques, including intricate manufacturing, nonlinear responses to changes in sweat rates, and errors from the intermediate measurement of the distance sweat travels in the sensor. To address these issues, we present a comprehensive wearable platform that includes a fully printed, flexible sensor patch, readout electronics, and a mobile app for continuous, real-time monitoring of sweat rate. We fabricate a sensor patch with an area of 700 mm2 and a weight of 380 mg by utilizing direct 3D printing and scalable microfluidic fabrication. The microfluidic channels are 850μm wide and 164μm thick, with serpentine electrodes measuring sweat rate using capacitance. The custom readout electronics capture these changes in capacitance to accurately measure sweat rate, achieving a sensitivity of 0.01μLmin−1. The sensor’s performance is validated against analytical models, simulations, and on-body trials with commercial sensors. This cost-effective, flexible, and fully integrated sweat-sensing solution has significant potential in precision health.

    @article{islam2024printed, title = {Printed Wearable Sweat Rate Sensor for Continuous In Situ Perspiration Measurement}, author = {Islam, Mohammad Shafiqul and Cha, Sangwon and Hassan, Md Farhad and Cai, Wenxin and Saniat, Tahsin Sejat and Leach, Cedar Rose and Khan, Yasser}, journal = {Advanced Intelligent Systems}, year = {2024}, publisher = {Wiley}, doi = {10.1002/aisy.202400927}, thumbnail = {islam2024printed.png}, url = {http://dx.doi.org/10.1002/aisy.202400927}, pdf = {islam2024printed.pdf} }

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