A Versatile and High-Resolution Hydrogel Platform for Volumetric Additive Manufacturing Based on Poly(ethylene glycol) Diacrylate and Alginate Blends

Volumetric additive manufacturing (VAM) has emerged as a potent method for fabricating complex structures out of soft materials such as hydrogels. In this study, a low-cost photopolymer platform is developed based on low molecular weight poly (ethylene glycol) diacrylate (PEGDA) and alginate (Alg) blends which reduces material costs ≈1000x. By adding non-crosslinked 0.5 wt.% of Alg to these 5, 10, or 15 wt.% PEGDA precursor solutions, the viscosity is raised from <1 mPa*s to 50 mPa*s, which enables VAM of low molecular weight PEGDA. The fabricated hydrogels have customizable mechanical properties, ranging from 14 ± 4 kPa to 90 ± 24 kPa, and 289 ±121 kPa and correspond to equilibrium water contents of 96.8 ± 0.3%, 91.2% ± 0.8% and 84.1% ± 0.9%. The printed structures have minimum feature sizes ranging between 56 ± 9 µm for 5 wt.% PEGDA + 0.5 wt.% Alg, 47 ± 12 µm for 10 wt.% PEGDA + 0.5 wt.% Alg, and 39 ± 7 µm for 15 wt.% PEGDA + 0.5 wt.% Alg. Additionally, these materials are printable into designs with internal voids, unsupported struts, and interlocked features. This work establishes a low cost, mechanically tunable hydrogel platform for VAM which can improve accessibility and adoption.