Abstract Flexible wearable sensors assembled from conductive hydrogels have received great attention due to their wide application in human-machine interfaces, medical and healthcare detection. However, the traditional conductive gel needs to be attached to the application surface with external force, and only respond to the single strain stimulus. Moreover, due to the existence of water, ordinary hydrogels cannot work at below zero temperatures, which severely limits the application of hydrogel-based flexible electronic devices. The flexible wearable epidermal sensors assembled by ultra-sensitive polyvinyl alcohol-tannic acid-eutectic gallium-indium (PVA-TA-EGaIn) hydrogels with adhesiveness, rapid self-healing, high electrical conductivity and mechanical properties, and temperature sensitivity. The rigid conductive hydrogel prepared by freeze-thaw cycles shows outstanding tensile/compressive strength (1.13 MPa/4.59 MPa) and toughness (1.9 MJ/m3), and reveals excellent fatigue resistance. It also exhibited high conductivity (3.63 S m−1) and strain sensitivity (gauge factor = 2.59). In addition, the hydrogels maintained good flexibility and conductivity at −10 °C. Besides, the PVA-TA-EGaIn hydrogels shows remoldability, which greatly prolongs the service life of the gel. The composite hydrogels show the potential of building the next generation of multifunctional hydrogel-based flexible wearable sensors in human motion monitoring, voice recognition and medical diagnosis.

中文翻译：

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用于仿生皮肤的具有离子液体金属双导电性的自修复、防冻、粘合和可重塑水凝胶传感器

摘要 由导电水凝胶组装而成的柔性可穿戴传感器因其在人机界面、医疗和保健检测方面的广泛应用而受到广泛关注。然而，传统的导电凝胶需要借助外力附着在应用表面，并且仅对单一应变刺激做出响应。而且，由于水的存在，普通水凝胶不能在零温度以下工作，这严重限制了水凝胶基柔性电子器件的应用。由超灵敏聚乙烯醇-单宁酸-共晶镓-铟（PVA-TA-EGaIn）水凝胶组装而成的柔性可穿戴表皮传感器具有粘附性、快速自愈性、高导电性和机械性能以及温度敏感性。通过冻融循环制备的刚性导电水凝胶显示出优异的拉伸/压缩强度（1.13 MPa/4.59 MPa）和韧性（1.9 MJ/m3），并显示出优异的抗疲劳性。它还表现出高电导率 (3.63 S m-1) 和应变敏感性（应变系数 = 2.59）。此外，水凝胶在-10°C 下仍保持良好的柔韧性和导电性。此外，PVA-TA-EGaIn水凝胶具有可塑性，大大延长了凝胶的使用寿命。复合水凝胶显示了在人体运动监测、语音识别和医疗诊断中构建下一代多功能水凝胶柔性可穿戴传感器的潜力。它还表现出高电导率 (3.63 S m-1) 和应变敏感性（应变系数 = 2.59）。此外，水凝胶在-10°C 下仍保持良好的柔韧性和导电性。此外，PVA-TA-EGaIn水凝胶具有可塑性，大大延长了凝胶的使用寿命。复合水凝胶显示了在人体运动监测、语音识别和医疗诊断中构建下一代多功能水凝胶柔性可穿戴传感器的潜力。它还表现出高电导率 (3.63 S m-1) 和应变敏感性（应变系数 = 2.59）。此外，水凝胶在-10°C 下仍保持良好的柔韧性和导电性。此外，PVA-TA-EGaIn水凝胶具有可塑性，大大延长了凝胶的使用寿命。复合水凝胶显示了在人体运动监测、语音识别和医疗诊断中构建下一代多功能水凝胶柔性可穿戴传感器的潜力。