Self-healing hydrogel plays an important role in flexible sensors. However, the development of high-performance hydrogel-based strain sensors with both high sensitivity and large sensing range remains a key challenge. Herein, we prepare a dual conductive network (DCN) hydrogel based on carbon nanotube (CNT) film and conductive hydrogel that exhibits high-conductivity, self-healing, anti-freezing, and non-drying features. The tolerance of this hydrogel to extreme temperatures is improved via a simple solvent replacement, enabling the DCN hydrogel to maintain high flexibility and stretchability under arduous conditions such as temperatures ranging from −85 to 50 °C. Additionally, owing to the dual conductive percolation network structure, the strain sensor based on DCN hydrogel exhibits a gauge factor as high as 343 at a strain of 110%, indicating high sensitivity. The mechanical and electrical performances of the hydrogel would be efficiently self-repaired after a simple heating–cooling treatment. The self-healing sensor can be mounted on the human body to detect biosignals in real time. Our work shows a method of fabricating high-performance self-healing hydrogel for future flexible electronics.

中文翻译：

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双导电网络水凝胶，用于高导电，自修复，防冻和非干燥应变传感器

自修复水凝胶在柔性传感器中起着重要作用。然而，具有高灵敏度和大传感范围的高性能基于水凝胶的应变传感器的开发仍然是关键的挑战。本文中，我们基于碳纳米管（CNT）膜和导电水凝胶制备了双导电网络（DCN）水凝胶，该凝胶具有高导电性，自愈，防冻和不干燥的特性。通过简单的溶剂替换，可以改善这种水凝胶对极端温度的耐受性，从而使DCN水凝胶在恶劣的条件下（例如-85至50°C的温度）能够保持较高的柔韧性和可拉伸性。此外，由于采用了双重导电渗滤网络结构，基于DCN水凝胶的应变传感器在110％应变下的应变系数高达343，表示高灵敏度。经过简单的加热-冷却处理后，水凝胶的机械和电气性能将得到有效的自我修复。自愈传感器可以安装在人体上，以实时检测生物信号。我们的工作展示了一种制造用于未来柔性电子产品的高性能自修复水凝胶的方法。