Hydrogels exhibit promising applications, particularly due to their high water content and excellent biocompatibility. Despite notable progress in hydrogel technology, the concurrent enhancement of water content, mechanical strength, and low friction poses substantial challenges to practical utilization. In this study, employing molecular and network design guided based on multiple synergistic enhancement mechanisms, we have developed a robust polyvinyl alcohol (PVA)–polyacrylic acid (PAA)–polyacrylamide (PAAm) three-network (TN) hydrogel exhibiting high water content, enhanced strength, low friction, and fatigue resistance. The hydrogel manifests a water content of 63.7%, compression strength of 6.3 MPa, compression modulus of 2.68 MPa, tensile strength reaching 7.3 MPa, and a tensile modulus of 10.27 MPa. Remarkably, even after one million cycles of dynamic loading, the hydrogel exhibits no signs of fatigue failure, with a minimal strain difference of only 1.15%. Furthermore, it boasts a low sliding coefficient of friction (COF) of 0.043 and excellent biocompatibility. This advancement extends the applications of hydrogels in emerging fields within biomedicine and soft bio-devices, including load-bearing artificial tissues, artificial blood vessels, tissue scaffolds, robust hydrogel coatings for medical devices, and joint parts of soft robots.

水凝胶具有广阔的应用前景，特别是由于其高含水量和优异的生物相容性。尽管水凝胶技术取得了显着进展，但水含量、机械强度和低摩擦力的同时提高给实际应用带来了巨大挑战。在这项研究中，采用基于多种协同增强机制的分子和网络设计指导，我们开发了一种坚固的聚乙烯醇（PVA）-聚丙烯酸（PAA）-聚丙烯酰胺（PAAm）三网络（TN）水凝胶，具有高含水量，增强强度、低摩擦和抗疲劳性。该水凝胶的含水量为63.7%，压缩强度为6.3 MPa，压缩模量为2.68 MPa，拉伸强度达到7.3 MPa，拉伸模量为10.27 MPa。值得注意的是，即使经过一百万次动态加载循环，水凝胶也没有表现出疲劳失效的迹象，最小应变差异仅为 1.15%。此外，它还具有0.043的低滑动摩擦系数（COF）和优异的生物相容性。这一进展扩展了水凝胶在生物医学和软生物设备新兴领域的应用，包括承重人造组织、人造血管、组织支架、用于医疗设备的坚固水凝胶涂层以及软机器人的关节部件。