A fiber-shaped sensor constructed by coaxial wet-spinning for dual-mode sensing†

Abstract

With the booming development of smart electronic devices, the forms of wearable sensors are gradually diversifying. However, integrating dual sensing capabilities into a single sensor for decoupled strain and humidity detection remains a significant challenge. In this study, we report a flexible dual-modal sensor designed with a “skin–core” structure that integrates pressure and humidity sensing layers, enabling decoupled monitoring of pressure and humidity. Using a coaxial wet-spinning method, we fabricated multifunctional sensing fibers with MXene/CNF as the core and cationic cellulose as the skin. By controlling the ratio of the spinning solution for the core layer, the resulting MXene/CNF@cationic cellulose aerogel fiber (MCC) pressure sensor exhibits high sensitivity (120 kPa⁻¹), rapid response time (50 ms for response, 55 ms for recovery), and excellent cycling stability under compression. Furthermore, the unique structure of the coaxially spun aerogel and the inherent properties of the MCC fiber material endow the sensor with outstanding cycling stability, fast moisture absorption and desorption responses (response time of 9.43 s and recovery time of 5.3 s), and excellent moisture absorption and desorption characteristics. This study promotes the effective utilization of cellulose-based materials in wearable sensing and health management, expands how sensors can be worn, and lays the foundation for the integration of sensors with garments.