Over the past century, hydrogels have emerged as effective materials for an immense variety of applications. The unique network structure of hydrogels enables very high levels of hydrophilicity and biocompatibility, while at the same time exhibiting the soft physical properties associated with living tissue, making them ideal biomaterials. Stimulus-responsive hydrogels have been especially impactful, allowing for unprecedented levels of control over material properties in response to external cues. This enhanced control has enabled groundbreaking advances in healthcare, allowing for more effective treatment of a vast array of diseases and improved approaches for tissue engineering and wound healing. In this extensive review, we identify and discuss the multitude of response modalities that have been developed, including temperature, pH, chemical, light, electro, and shear-sensitive hydrogels. We discuss the theoretical analysis of hydrogel properties and the mechanisms used to create these responses, highlighting both the pioneering and most recent work in all of these fields. Finally, we review the many current and proposed applications of these hydrogels in medicine and industry.

中文翻译：

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刺激响应水凝胶：理论、现代进展和应用。

在过去的一个世纪中，水凝胶已成为适用于各种应用的有效材料。水凝胶独特的网络结构具有非常高水平的亲水性和生物相容性，同时表现出与活体组织相关的柔软物理特性，使其成为理想的生物材料。刺激响应水凝胶尤其具有影响力，可以根据外部提示对材料特性进行前所未有的控制。这种增强的控制实现了医疗保健领域的突破性进步，可以更有效地治疗多种疾病，并改进组织工程和伤口愈合的方法。在这篇广泛的综述中，我们确定并讨论了已开发的多种响应模式，包括温度、pH、化学、光、电和剪切敏感水凝胶。我们讨论了水凝胶特性的理论分析以及用于产生这些响应的机制，重点介绍了所有这些领域的开创性和最新工作。最后，我们回顾了这些水凝胶在医学和工业中的许多当前和拟议的应用。