A Fully Printable and Integrated System with Long-Term Stability for Versatile and Multimodal Perspiration Tracking

Real-time and continuous monitoring of physiological status via noninvasive sweat sensing shows promise for personalized healthcare and fitness management. However, the largely varied perspiration rates in different body statuses introduce challenges for effective sweat collection and accurate sensing. Herein, a fully printable strategy was developed to realize fully integrated patches for wireless sensing of sweat biomarker levels and perspiration rates with desirable stability and versatility. The printable calcium sensors with modified ion-selective membranes displayed an ultrawide linear range of 0.1-100 mM and a long-term stability with minimized drift down to 0.083 mV/h for around 40 h. Moreover, the microfluidic channels in versatile configurations were capable of a minimum sweat rate monitoring of 0.5 μL/min and a large sweat storage volume of up to 200 μL. The as-proposed fully printable sensing platforms provide high compatibility for sensor integration to achieve versatile perspiration tracking and comprehensive health monitoring.