Skin-like hydrogels: design strategy and mechanism, properties, and sensing applications

Abstract

Human skin is soft, stretchable, elastic, has a strong ability to heal when injured, and can sense various stimuli. Therefore, the development of materials that can simulate skin characteristics has high research value. Hydrogel is a three-dimensional network material with high water content, which has a high potential for the development of skin-like materials. However, traditional hydrogels are often fragile and have poor sensing ability, which are greatly different from the same properties of skin. Skin-like hydrogel can effectively solve the above problems of traditional hydrogels due to its mechanical tunability, excellent stimulation detection ability and other properties. It is a potential skin-like material. Thus, this study first reviews the design strategy and mechanism of skin-like hydrogels, that is, how to develop qualified skin-like hydrogels, including toughening, stimulation perception and transmission, self-healing and biocompatibility. Secondly, in order to be more suitable for practical application, this study also introduces the methods of introducing adhesion, self-power, and freezing resistance to the skin-like hydrogel. Besides, considering the important enlightening significance of skin in sensing, this study introduces the application of skin-like hydrogels in the field of sensing (namely mechanical sensing, temperature sensing, biochemical sensing). Finally, this study reviews the difficulties and deficiencies in the current research process of skin-like hydrogel and looks forward to its future development.