Soft Yet Tough Tanglemers Through Rapid Photopolymerization for DLP 3D Printing

Additive manufacturing of compliant materials that simultaneously combine softness, elasticity, and toughness remains a central challenge. Here, we report a single-resin photopolymerization strategy to produce densely entangled polymer networks ("tanglemers") via digital light processing (DLP) 3D printing using industrially abundant monomers. Comparisons between controlled and uncontrolled radical polymerizations reveal that the uncontrolled, free-radical approach at low initiator loadings and light intensities balances DLP-relevant gelation timescale with high molecular weight between crosslinks. The resulting elastomers and hydrogels exhibit a rare combination of properties, including low modulus (E_T <1 MPa for elastomers and <100 kPa for hydrogels), high extensibility (ε_f > 400%), low hysteresis (∼10%), and high toughness (U_t > 1 MJ m^{- 3}, G_c ≈ 1 kJ m^{- 2} for elastomers; U_t ≈ 1 MJ m^{- 3}, G_c ≈ 3 kJ m^{- 2} for hydrogels). These materials translate from casting to DLP 3D printing with feature sizes down to ∼100 µm, surpassing commercial resins in softness and elasticity, while maintaining competitive toughness and aging resistance after initial accelerated weathering. This work establishes simple, single-resin formulations as a route to DLP-printable, defect-tolerant tanglemers with potential relevance to soft robotic, wearable, and biomedical technologies.