# Strain and Electromyography Dual-Mode Stretchable Sensor for Real-Time Monitoring of Joint Movement

## TL;DR

This paper introduces a stretchable sensor that can simultaneously monitor joint movement and muscle activity, transmitting data wirelessly for real-time analysis.

## Contribution

A dual-mode stretchable sensor system for synchronized strain and EMG detection with wireless transmission for real-time joint monitoring.

## Key findings

- The sensor system achieves >80% stretchability and >4000-cycle durability with fast response times.
- Position-independent strain measurement enables accurate joint angle detection regardless of placement.
- The system supports real-time data visualization on mobile and desktop platforms.

## Abstract

Flexible sensors have emerged as critical interfaces for information exchange between soft biological tissues and machines. Here, we present a dual-mode stretchable sensor system capable of synchronous strain and electromyography (EMG) signal detection, integrated with wireless WIFI transmission for real-time joint movement monitoring. The system consists of two key components: (1) A multi-channel gel electrode array for high-fidelity EMG signal acquisition from target muscle groups, and (2) a novel capacitive strain sensor made of stretchable micro-cracked gold film based on Styrene Ethylene Butylene Styrene (SEBS) that exhibits exceptional performance, including >80% stretchability, >4000-cycle durability, and fast response time (<100 ms). The strain sensor demonstrates position-independent measurement accuracy, enabling robust joint angle detection regardless of placement variations. Through synchronized mechanical deformation and electrophysiological monitoring, this platform provides comprehensive movement quantification, with data visualization interfaces compatible with mobile and desktop applications. The proposed technology establishes a generalizable framework for multimodal biosensing in human motion analysis, robotics, and human–machine interaction systems.