Self-healing hydrogels have attracted intense attention because of their potential applications in ionic strain sensors. However, most self-healing hydrogel sensors exhibit poor mechanical properties due to the inherent compromise between the dynamic interactions for healing and steady interactions for mechanical strength. Here, strong, tough and self-healing ionic conductive hydrogel sensors were prepared based on synergistic multiple noncovalent bonds among carboxymethyl guar gum (CMGG), poly(acrylic acid) (PAA), and ferric metal ions (Fe³⁺) in a covalent polymer network. The incorporated CMGG, mediated by metal–ligand interactions, acts as dynamic cross-linkers, endowing the ionic hydrogels with superior mechanical properties. In addition, the reversible and dynamic nature of the multiple metal–ligand interactions accounts for the good self-recovery capabilities, remarkable mechanical properties, and high self-healing efficiencies. Furthermore, the ionic conductive hydrogels displayed good strain sensitivity with repeatable, reliable, and precise changes of resistance signals. Based on these merits, the hydrogel could be assembled as a flexible strain sensor to monitor and distinguish various human motions. We expect that this facile method of incorporating the biocompatible and biodegradable CMGG for the design of strong, tough, self-healing and ionic conductive hydrogels may have promising potential for flexible strain sensors for human motion monitoring.

中文翻译：

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开发用于人体运动检测的高强度，坚韧，可自愈的羧甲基瓜尔胶基水凝胶†

自修复水凝胶由于其在离子应变传感器中的潜在应用而备受关注。然而，由于用于修复的动态相互作用与用于机械强度的稳定相互作用之间固有的折衷，大多数自修复水凝胶传感器表现出较差的机械性能。在此，基于羧甲基瓜尔胶（CMGG），聚丙烯酸（PAA）和三价金属离子（Fe ³⁺）在共价聚合物网络中。通过金属-配体相互作用介导的结合的CMGG，充当动态交联剂，赋予离子水凝胶以优异的机械性能。此外，多种金属-配体相互作用具有可逆性和动态性，因此具有良好的自我恢复能力，出色的机械性能和较高的自我修复效率。此外，离子导电水凝胶显示出良好的应变敏感性，并具有可重复，可靠和精确的电阻信号变化。基于这些优点，可以将水凝胶组装为柔性应变传感器，以监视和区分各种人体运动。我们希望这种结合生物相容性和可生物降解的CMGG的简便方法可用于设计坚固，坚固，