Abstract：Hydrogels have received increasing attention for their wide range of applications in flexible wearable devices, bionic actuators and biomedicine. However, the mechanical properties of conventional hydrogels are poor. Inspired by muscle training, this paper proposes a new method combining the ice template method and mechanical training to prepare anisotropic strong hydrogels, and analyses the effects of different training times on their mechanical properties. In the preparation process, PVA was first dispersed in deionised water and heated and stirred to form a homogeneous solution, which was then slowly dripped into a mould and frozen with liquid nitrogen from the bottom up to form a PVA hydrogel with a fibrous structure. This hydrogel was then immersed in a glycerol-water mixture and mechanically trained using a homemade cyclic tensile tester. The mechanical properties of hydrogels prepared by different methods were tested. The results showed that the anisotropic hydrogels prepared by the ice template method had a distinct fiber structure, but their fiber orientation was significantly dispersed. After mechanical training, the fiber orientation of the hydrogels became highly consistent and more compact. The mechanical properties of the hydrogels were significantly improved by the combination of the ice template method and the mechanical training method. In addition, an anisotropic hyperelastic constitutive model is proposed, which takes into account compositional variations and fiber orientation. By comparing with the experimental results, it is verified that the model can effectively describe the mechanical behaviour of hydrogels. This study provides a new method for preparing anisotropic strong hydrogels and a theoretical basis for predicting and analysing their mechanical responses.
2025, Vol. 46 
