The limited anti-fatigue performance of self-healing polyurethane elastomers under high-strain conditions restricts their application in high-performance ionic skins. Herein, a polyurethane network (PU-DDN) synergistically reversibly crosslinked by dynamic thiourethane bonds and hydrogen bonds was synthesized successfully. This dual reversibly crosslinking strategy not only endowed the polyurethane network with an excellent fatigue resistance (showing a residual strain of only 63 % after 10 uninterrupted cyclic tensile tests at 400 % strains), but also imparted it with a high strength (6.12 MPa) and stretchability (611.42 %). Owing to the thermo-reversibility of dual dynamic networks, the damaged PU-DDN heated at 100 °C for 3h could fully restore its initial mechanical properties. Subsequently, transparent stretchable ionic skins were fabricated by mixing the PU-DDN with ionic liquids. A resulting highly-sensitive ionic skin (GF1 = 1.25, GF2 = 2.01) named PU-DDN/IL20 demonstrated exceptional durability, which could produce repeatable electrical signals even after 2000 cycles of stretching to an extensive deformation of 400 %. Meanwhile, it can also monitor human motions, showcasing its promising potential in the realm of intelligent wearable applications.

中文翻译：

---

制造双动态交联聚氨酯网络以实现自修复、抗疲劳和高拉伸离子皮肤


自修复聚氨酯弹性体在高应变条件下的抗疲劳性能有限，限制了其在高性能离子皮肤中的应用。在此，成功合成了通过动态硫氨酯键和氢键协同可逆交联的聚氨酯网络（PU-DDN）。这种双重可逆交联策略不仅赋予聚氨酯网络优异的抗疲劳性能（在400%应变下进行10次不间断循环拉伸试验后残余应变仅为63%），而且赋予其高强度（6.12 MPa）和拉伸性（611.42%）。由于双动态网络的热可逆性，受损的PU-DDN在100℃下加热3小时可以完全恢复其初始机械性能。随后，通过将 PU-DDN 与离子液体混合来制备透明的可拉伸离子皮肤。由此产生的名为 PU-DDN/IL20 的高度敏感离子皮肤（GF1 = 1.25，GF2 = 2.01）表现出卓越的耐用性，即使在 2000 次拉伸至 400% 的大变形后，也可以产生可重复的电信号。同时，它还可以监测人体动作，展示了其在智能可穿戴应用领域的巨大潜力。