A Single Carbon Microyarn-Based Integrated Wearable Textile Sweat Sensor Built into a Hook-and-Loop Fastener

By fusing wearable sweat sensors for on-body sweat monitoring with textiles for daily wear, wearable textile sweat sensors (WTSSs) demonstrate the distinctive capability to monitor perspiration in real time while engaging in daily activities. However, previous WTSSs mainly focused on "weave-in-textile" or "print-on-textile" ones, which are permanently immobilized on specific regions of specific types of textiles prior to use and, accordingly, cannot be used in some specific routine circumstances (e.g., temporary changes in textile type/immobilization region). Here, in an alternative "stick-to-textile" approach, the first example of a single carbon microyarn-based integrated WTSS that is built into a hook-and-loop fastener (SI@HLF) for on-body, dynamic, and multiplexed sweat monitoring is reported. This system integrates a surface-engineered, loop-based antigravity transport module for directional sweat transport; a single carbon microyarn-based sensing array module for sweat biomarker analysis; a printed circuit board (PCB)-based data processing module for monitoring and control; and an adhesive module based on a patterned adhesive film on the loop for universal immobilization. We tested the performance of SI@HLF in healthy subjects under controlled trials simulating daily exercise. We also evaluated the utility of SI@HLF when immobilized on various types of textiles and textile regions during routine activities.