We investigate pattern transformations of periodic hydrogel systems that are triggered by swelling-induced structural instabilities. The types of microstructures considered in the present work include single-phase and two-phase voided hydrogel structures as well as reinforced hydrogel thin films. While the observed transformations of the single-phase structures show good agreement with experimental findings, the two-phase materials provide novel patterns associated with wrinkling of internal surfaces. Furthermore, an extensive parametric study on the reinforced hydrogel thin films reveals new opportunities for the design of complex out-of-plane surface modes caused by swelling-induced instabilities. Next to the mentioned buckling-type instabilities, we encountered the development of micro-creases at the internal surfaces of periodic media.

我们研究了由膨胀引起的结构不稳定性触发的周期性水凝胶系统的模式转换。目前工作中考虑的微观结构类型包括单相和两相空隙水凝胶结构以及增强水凝胶薄膜。虽然观察到的单相结构转变与实验结果非常吻合，但两相材料提供了与内表面起皱相关的新模式。此外，对增强水凝胶薄膜的广泛参数研究揭示了设计由膨胀引起的不稳定性引起的复杂平面外表面模式的新机会。除了提到的屈曲型不稳定性之外，我们还遇到了周期性介质内表面微折痕的发展。