(562b) Highly Stretchable, Sensitive, and Self-Healable Wearable Strain Sensor Based on an Elastomeric Hierarchical Conductive Nanofiber Network

The demand for flexible and wearable electronic devices has dramatically increased with the advancement of microelectronics and nanotechnology. A wearable strain sensor which can monitor motions and deformations is of great importance in various fields such as healthcare, robotic systems, prosthetics, professional sports, defense, among others. An ideal strain sensor should be highly stretchable, sensitive, and robust enough for long-term use. It is inevitable for current strain sensors to degrade their performance or even fail due to consistent and dynamic extreme deformations or accidental damages. For this reason, the addition of self-healable nature for the designed strain sensor is highly needed. Here we present a strain sensor based on a hierarchical conductive nanofiber network with a designed stretchable structure embedded in a self-healing thermoplastic polymer. The conductive network is composed of highly conductive metal nanowires and inherent flexible conductive polymers. It can sustain the electric percolation network at a large strain with a significant change in resistance giving a high gauge factor (highly sensitive). The self-healable nature of matrix can be easily triggered by heat, IR light or electricity. The highly stretchable, sensitive, and self-healable strain sensor is able to accurately detect different types of human motions including joint movement, breathing, speech, pulse, among many others.