Despite their importance as components for flexible electronics, most stretchable hydrogels suffer from incomplete recovery after deformation, are prone to failure upon long-term repeated stretching, and cannot be exploited at subzero temperatures because of the freezing of their constituent water. Consequently, strategies for circumventing these drawbacks are highly sought after. This study describes the synthesis of a doubly (chemically and physically) crosslinked hydrogel from gelatin and methacrylic acid and demonstrates the suitability of this material for the fabrication of high-performance stretchable and environment-resistant supercapacitors and strain sensors. The performance of this supercapacitor (areal capacitance = 1,210.2 mF/cm at a current density of 1 mA/cm, maximum energy density = 158.8 μW⋅h/cm, maximum power density = 659.5 μW/cm) was superior to that of most of integrated supercapacitors reported to date and was hardly affected by stretchable, low temperatures, bending, ice-cold water and strong acid/alkali solutions or long-term storage. Additionally, a strain sensor based on the above hydrogel was capable of accurately capturing human body motions when affixed to skin and recognising mouse movement (even in humid environments) after implantation into mouse legs. Our work may pave the way to high-performance stretchable and environment-resistant wearable electronics.

中文翻译：

---

用于一体化超级电容器和应变传感器的可拉伸且耐环境的双交联水凝胶


尽管它们作为柔性电子器件的组件很重要，但大多数可拉伸水凝胶在变形后恢复不完全，在长期重复拉伸时容易失效，并且由于其成分水冻结而无法在零下温度下使用。因此，规避这些缺点的策略受到高度追捧。这项研究描述了由明胶和甲基丙烯酸合成的双（化学和物理）交联水凝胶，并证明了该材料适用于制造高性能可拉伸和耐环境的超级电容器和应变传感器。该超级电容器的性能（电流密度为 1 mA/cm 时，面积电容 = 1,210.2 mF/cm，最大能量密度 = 158.8 μW·h/cm，最大功率密度 = 659.5 μW/cm）优于大多数超级电容器的性能。迄今为止报道的集成超级电容器几乎不受拉伸、低温、弯曲、冰冷的水和强酸/碱溶液或长期储存的影响。此外，基于上述水凝胶的应变传感器在贴在皮肤上时能够准确捕获人体运动，并在植入小鼠腿部后识别小鼠的运动（即使在潮湿的环境中）。我们的工作可能为高性能可拉伸和耐环境的可穿戴电子产品铺平道路。