A Tough and Self-Powered Hydrogel for Artificial Skin

作者：Rumin Fu, Lingjie Tu, Yahong Zhou, Lei Fan, Fengmiao Zhang, Zhengao Wang, Jun Xing, Dafu Chen, Chunlin Deng, Guoxin Tan, Peng Yu, Lei Zhou, Chengyun Ning · 发表于：Chemistry of Materials · 年份：2019 · DOI：10.1021/acs.chemmater.9b04041 · 被引用次数：259 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Tactile and Sensory Interactions、Advanced Materials and Mechanics

Hydrogels, because of their water-rich nature and soft mechanical characteristics that resemble those of skin tissues, are promising materials for artificial skin. Existing piezoresistive hydrogels combine unique tissue-like and sensory properties, but these materials are often plagued by problems such as poor mechanical properties and the requirement of an external power supply or batteries. Here, a tough and self-powered hydrogel based on a tough polyacrylonitrile hydrogel incorporating ferroelectric poly(vinylidene fluoride) (PAN-PVDF) is reported. The dipolar interactions between the PVDF and PAN chains cause an increase in the best electroactive β-phase PVDF percentage in the composites from 0 to 91.3%; thus, a maximum piezoelectric coefficient d 33, 30 pC N –1, was achieved for the hydrogels. Skin-like Young’s modulus values (1.33–4.24 MPa), stretchability (90–175%), and high toughness (1.23 MJ/m 2 ) were achieved simultaneously for the hydrogels. This tough gel is capable of generating an electrical signal output (≈30 mV and ≈2.8 μA) with a rapid response (≈31 ms) due to the stress-induced poling effect. Moreover, the gel can also precisely detect physiological signals (e.g., gesture, pulse, and words). This study provides a simple and efficient method for artificial skin with high toughness, self-power generation capability, fast response, low cost, and tissue-like properties.