다기능 웨어러블 센서용 셀룰로오스 기반 신축전도성 필름

Abstract

The development of sustainable, multifunctional wearable sensors has gained increasing attention for real-time health monitoring and next-generation healthcare applications. In this study, a stretchable and conductive hybrid film based on carboxymethyl cellulose (CMC), tannic acid (TA), and sodium chloride (NaCl), was fabricated to address the need for biocompatible and environmentally friendly sensor platforms. CMC provided the flexible structural matrix due to its high water solubility and biocompatibility, while TA introduced multiple hydrogen bonding networks via its phenolic hydroxyl groups, significantly improving the mechanical strength and structural stability. Furthermore, ionic crosslinking was induced through Na+ coordination with carboxylate groups, facilitating efficient ion-conductive pathways. As a result, the CMC/TA/NaCl film exhibited excellent mechanical durability, achieving a maximum tensile strain of 313.01% and a maximum tensile strength of 0.683MPa. The film maintained stable electrical conductivity under various deformations such as stretching, twisting, and bending, and demonstrated reliable strain sensing behavior with rapid response and recovery, as well as durability over repeated deformation cycles. In addition, the incorporation of TA endowed the film with ultraviolet shielding capability while maintaining high optical transparency. The film successfully detected diverse physiological signals, including joint motion, skin deformation, swallowing, pressure changes, temperature variations, and humidity changes during phonation. The developed CMC/TA/NaCl film presents a promising material platform for on-skin wearable sensors and will contribute to the realization of multifunctional, high-performance, and eco-friendly wearable devices for next-generation healthcare monitoring.