Superwetting Gels: Wetting Principles, Applications, and Challenges

Along with the in-depth understanding of wetting behaviors in nature, superwetting gels have received a lot of attention in the past decade. The viscoelasticity of gel materials makes wetting characteristics different from those of rigid materials and brings diverse functionality. In this Review, we summarize the current progress in principles of gel wettability from two aspects: wetting on gels and wetting of gels. Distinct from rigid substrates, the viscoelasticity and solid-liquid coexistence of gel materials introduce additional factors, including surface tension and deformation, resulting in various wetting phenomena. Besides, the similarity between gels and tissues broadens its applications in biomedical devices and smart interfacial regulation. We further conclude the current application that utilizes superwetting gels. Finally, we provide our perspective for future research directions.