Savolainen Henri, Hosseiniyan Negar, Piedrahita-Bello Mario, Ikkala Olli
Department of Applied Physics, Aalto University, Espoo, Finland.
Nat Commun. 2025 May 15;16(1):4544. doi: 10.1038/s41467-025-59743-w.
Nature suggests concepts for materials with efficient mechanical energy storage and release, i.e., resilience, involving small energy dissipation upon mechanical loading and unloading, such as in resilin and elastin. These materials facilitate burst-like movements involving high stiffness and low strain and high reversibility. Synthetic hydrogels that allow highly reversible mechanical energy storage have remained a challenge, despite mimicking biological soft tissues. Here we show a synthetic concept using fixed hydrogel polymer compositions based on sequentially swollen and sequentially photopolymerized gelation steps for hierarchical networks. The sequential swellings facilitate the balance of properties between resilience and dissipation upon controlling of the chain extension. At low hierarchical levels, we show resilience with small hysteresis with increased stiffness and resilient energy storage, whereas at high hierarchical levels, a transition is shown to a dissipative and considerably reinforced state. The generality of this approach is shown using several photopolymerizable monomers.
自然界为具有高效机械能存储和释放功能的材料（即弹性）提供了概念，例如在弹性蛋白和弹性硬蛋白中，这种材料在机械加载和卸载时能量耗散小。这些材料有助于实现爆发式运动，这种运动具有高刚度、低应变和高可逆性。尽管合成水凝胶模仿了生物软组织，但实现高度可逆的机械能存储仍然是一个挑战。在这里，我们展示了一种合成概念，即使用基于顺序溶胀和顺序光聚合凝胶化步骤的固定水凝胶聚合物组合物来构建分级网络。顺序溶胀有助于在控制链延伸时平衡弹性和耗散之间的性能。在低分级水平下，我们展示了具有小滞后的弹性，同时刚度和弹性能量存储增加，而在高分级水平下，则显示出向耗散且显著增强状态的转变。使用几种可光聚合单体展示了这种方法的通用性。
