Micelle–Micelle Cross-Linked Highly Stretchable Conductive Hydrogels for Potential Applications of Strain and Electronic Skin Sensors

作者：Mansoor Khan, Luqman Ali Shah, Latafat Ara, Rafi Ullah, Hyeong-Min Yoo · 发表于：Chemistry of Materials · 年份：2023 · DOI：10.1021/acs.chemmater.3c01092 · 被引用次数：71 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Muscle activation and electromyography studies、Electrospun Nanofibers in Biomedical Applications

Wearable sensors made of flexible and stretchable hydrogels have garnered significant attention. However, their use has been limited by poor mechanical performance, such as poor toughness, poor self-recovery, and a large response–recovery time. To overcome these limitations, we have developed a novel cross-linking agent-based hydrogel with high stretchability, high toughness, antifatigue properties, and good conductivity. These hydrogels were developed by introducing l -glutamic acid (LGA) into hydrophobically cross-linked polyacrylamide (PAmm) chains. In this system, LGA dynamically cross-linked the micelle–micelle and micelle–polymer chains and greatly regulates the mechanical properties of the hydrogels. The noncovalent synergistic interactions that came with the insertion of LGA enable the hydrogels to achieve high stretchability and high stress values, with fast self-recovery and antifatigue behaviors without the help of foreign stimuli. Additionally, LGA-based hydrogels can function as durable and highly sensitive strain sensors for detecting various mechanical deformations with a fast response–recovery time and high gauge factor value. As a result, the hydrogels have the capability to be designed as wearable strain sensors that are capable of detecting large human joint motions, such as neck twisting, neck bending, and wrist, finger, and elbow movements. Similarly, these hydrogels are capable of monitoring different subtle human motions such as speaking and differentia...