Functionalized Cellulose-Based Wearable Textile Detection from Insensible Sweat to a Multiparameter Biomarker in Sensible Sweat

Abstract

Sweat is a key physiological fluid involved in regulating body temperature and maintaining hydration balance. Compared with sensible sweat, insensible sweat is continuously lost in the form of water vapor. Its dynamic variation is closely associated with skin barrier function and basic thermoregulatory activity. However, its low flux and diffuse distribution make reliable detection challenging. In addition, multiparameter analysis of biochemical components in sensible sweat is of significant importance for the evaluation of electrolyte balance and physiological status. In this work, a multiparameter textile platform based on functionalized cellulose materials was developed for monitoring and analyzing the sweating process. Cellulose was employed as the core material platform. By incorporating lithium chloride, humidity-responsive units were fabricated and further configured into a scalable fabric-integrable array, enabling the detection of subtle humidity variations induced by low-flux insensible sweat. As thermal load increased and the system transitioned to the sensible sweating stage, electrochemical sensing fibers were integrated. In combination with the sweat absorption and transport capability of cellulose yarns, the platform enabled the determination of key biochemical parameters in sensible sweat, including pH, sodium, potassium, and uric acid. On-body sweat analysis demonstrated that the textile system enables array-based monitoring of insensible sweat, during the transition to the sensible sweating stage, allowing simultaneous acquisition of multiple physiological parameters. This integrated capability provides a promising approach for continuous monitoring and evaluation of the human sweat rate, electrolyte balance, and related physiological conditions.