Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, China.
Department of Physics, Nanjing University, Nanjing, China.
Nat Commun. 2022 Apr 27;13(1):2279. doi: 10.1038/s41467-022-30021-3.
Ligaments are flexible and stiff tissues around joints to support body movements, showing superior toughness and fatigue-resistance. Such a combination of mechanical properties is rarely seen in synthetic elastomers because stretchability, stiffness, toughness, and fatigue resistance are seemingly incompatible in materials design. Here we resolve this long-standing mismatch through a hierarchical crosslinking design. The obtained elastomer can endure 30,000% stretch and exhibit a Young's modulus of 18 MPa and toughness of 228 MJ m, outperforming all the reported synthetic elastomers. Furthermore, the fatigue threshold is as high as 2,682 J m, the same order of magnitude as the ligaments (~1,000 J m). We reveal that the dynamic double-crosslinking network composed of Li-O interactions and PMMA nanoaggregates allows for a hierarchical energy dissipation, enabling the elastomers as artificial ligaments in soft robotics.
韧带是关节周围的柔韧而坚硬的组织，用于支撑身体运动，表现出优异的韧性和耐疲劳性。这种机械性能的组合在合成弹性体中很少见，因为在材料设计中，拉伸性、刚性、韧性和耐疲劳性似乎是不相容的。在这里，我们通过分级交联设计解决了这一长期存在的不匹配问题。所得到的弹性体可以承受 30000%的拉伸，杨氏模量为 18 MPa，韧性为 228 MJ m，优于所有已报道的合成弹性体。此外，疲劳阈值高达 2682 J m，与韧带相当（~1000 J m）。我们揭示了由 Li-O 相互作用和 PMMA 纳米聚集体组成的动态双重交联网络允许分层能量耗散，使弹性体成为软机器人中的人工韧带。
