离子模板交联法调控聚乙烯醇/海藻酸钠水凝胶的可控变形行为

A versatile ionic crosslink lithography method was designed to prepare strong physically cross- linked polyvinyl alcohol/sodium alginate (PVA/SA) hydrogels and the three-dimensional deformation in a control- lable manner was achieved. For the selective cross-linking, the localized PVA/SA and PVA/SA/Fe^{3 +} hydrogel do- mains with significant differences in swellabilities in a PVA/SA hydrogel sheet. According to a simple 2-step se- quential pre- and free-swelling, the patterned hydrogel sheet could be directed to a controllable transformation and specific configurations through local bulging and/or global buckling. This type of shape changing is reversible and repeatable due to the reversibility of ionic coordination in the hydrogel networks. Further, a hydrogel with anisotro- py in plane gradient and thickness gradient could be constructed to achieve controllable deformation such as helix and bending in 3D printing. This ionic crosslink lithography method developed in this work may have certain appli- cation prospects in the development of wearable software sensors and software drivers, and it provides reference for the further development and application of hydrogels.