A High‐Performance, Sensitive, Wearable Multifunctional Sensor Based on Rubber/CNT for Human Motion and Skin Temperature Detection

TLDR

Flexible wearable electronics promise healthcare monitoring, motion detection, and sensory skins, yet most sensors suffer from limited stretchability, sensitivity, strength, conductivity, and single‑functionality. The authors designed and fabricated a hydrogen‑bond cross‑linked network of carboxylic styrene butadiene rubber and sericin‑modified carbon nanotubes to create multifunctional sensors. The hydrogen‑bond cross‑linked XSBR/SS‑CNT network provides the structural basis for the sensor’s high stretchability and conductivity. The XSBR/SS‑CNT sensor achieves 1 % strain detection, 217 % stretchability, 12.58 MPa strength, gauge factor 25.98, conductivity 0.071 S m⁻¹, percolation threshold 0.504 wt %, and a thermal sensitivity of 0.01636 °C⁻¹, enabling real‑time monitoring of motion and body temperature for wearable AI applications.

Abstract

Recently, flexible wearable electronic devices have attracted immense interest as an alternative for conventional rigid metallic conductors in personal healthcare monitoring, human motion detection, and sensory skins, owing to their intrinsic characteristics. However, the practical applications of most wearable sensors are generally limited by their poor stretchability and sensitivity, unsatisfactory strength, lower conductivity, and single sensory function. Here a hydrogen bond cross-linked network based on carboxylic styrene butadiene rubber (XSBR) and hydrophilic sericin (SS) non-covalently modified carbon nanotubes (CNTs) is rationally designed and then fabricated into multi-functional sensors. The resultant versatile sensors are able to detect both weak and large deformations, which owns a low detection limit of 1% strain, high stretchability up to 217%, superior strength of 12.58 MPa, high sensitivity with a gauge factor up to 25.98, high conductivity of 0.071 S m-1 , and lower percolation threshold of 0.504 wt%. Moreover, the prepared sensors also possess an impressively thermal response (0.01636 °C-1 ) and realize the application in the measurement of human body temperature. The multifunctional and scalable XSBR/SSCNT sensor with the integrated tracking capabilities of real-time and in situ physiological signals, providing a promising route to develop wearable artificial intelligence in human health and sporting applications.