Fabrication of Complex 3D Fluidic Networks via Modularized Stereolithography

Abstract

Stereolithography (SL) 3D printing has been widely applied for the fabrication of microchannels with photocurable resins and hydrogels, albeit with limitations in complexity and dimensions of attainable microchannels due to inadvertent polymerization of trapped photoresin within the channel voids and difficulty in evacuating trapped photoresin from channels after printing. Herein, a novel approach to circumvent these limitations by modularizing the fluidic network into printable subunits and assembling the printed subunits to reconstruct the fluidic network is proposed. This approach is validated by fabricating 2D and 3D hierarchical branching networks, lattice fluidic networks, helical channels, and serpentine channels, all of which are difficult to fabricate by a single attempt of 3D printing. The proposed approach offered 1) improves channel dimensions (channel w = 75 μm and h = 90 μm) and 2) increases complexity of fluidic network (up to 36 branching points). The principle of this approach is applicable to any SL printer and photocurable material for the fabrication of 3D microchannels. This approach should find applications in engineering tissue constructs recapitulating the complex 3D architecture of their vasculatures.