Continuous Preparation of the Record Strength and Toughness Hydrogel Fibers with a Homogeneous Crosslinked Network by Microcrystalline Dispersed Growth

Homogeneous crosslinked networks can achieve a balance between the strength and toughness of various biological materials, yet continuous synthesis of such networks remains challenging. Here, a strategy involving microcrystal dispersed growth to continuously fabricate hydrogel fibers with a homogeneous crosslinked network through wet spinning is reported. Rapid phase separation induced by solvent exchange under dense entanglement results in a uniform microcrystalline crosslinked network. Salting‐out induced crystal growth within the densified structure, while orientation and structural densification are achieved with the presence of a sacrificial salt template. Through the integration of nucleation, growth, and orientation, the homogeneous crosslinked network is constructed within the hydrogel matrix. Therefore, the strongest hydrogel fiber so far, which also exhibits a range of tunable properties, including strength (0.32 –141.66 MPa) and toughness (0.43 –157.93 MJ m⁻ 3 ) across a high‐water content range (40.6% to 86.8%) is reported. This design approach provided a viable strategy for the continuous preparation of ultra‐strong and tough hydrogels with a homogeneous crosslinked network.