Development of wearable self-healable strain sensor utilizing nano-composite materials for advanced sensing applications

Abstract

Wearable self-healable strain sensors are gaining significant attention for applications in healthcare, robotics, and human–computer interaction. However, existing sensors face key challenges, including limited healing efficiency, low sensitivity to mechanical strain, and inadequate durability under repeated stress. Addressing these limitations, this study presents a novel strain sensor combining a polyurethane (PU) substrate with magnetic iron oxide nanoparticles (MIONPs) and silver flakes to enhance self-healing capabilities and strain sensitivity. The integration of MIONPs enables a self-healing efficiency of 96.6% within 24 h, a notable improvement over previous technologies that often require longer recovery times and achieve lower healing rates. Additionally, the sensor achieves a high gauge factor of 271.4 at 35% strain, representing a fourfold increase in sensitivity compared to traditional strain sensors. The sensor's responsiveness to external magnetic fields, with a magnetic sensitivity of 0.0049 T⁻¹, further expands its application potential in areas like magnetically controlled devices and soft robotics. This work significantly advances multifunctional, self-healing strain sensors by addressing current limitations and offering improved performance for long-term, sustainable applications.