Direct-ink-write 3D printing of “living” polymer hydrogels via type I photoinitiated RAFT polymerization

Abstract

“Living” hydrogel photoinks based on the type I photoinitiated reversible addition/fragmentation chain transfer (RAFT) polymerization mechanism were formulated for use in a direct-ink-write (DIW) 3D printer. “Living” hydrogel cubes were 3D printed from these photoinks which could undergo post-production network modification through the insertion of new monomers into the polymer matrix. The multiple extruders of the DIW 3D printer were also exploited to 3D print multimaterial hydrogel objects. The “living” material sections swelled more extensively, leading to a swell-induced bending effect in the macroscopic multimaterial object.