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.

Vat Photopolymerization 3D Printing of Advanced Soft Sensors and Actuators: From Architecture to Function

“…[ 122 ] Functional elements, such as valves and pumps, can be precisely integrated into the device to ensure the control and direction of fluid flow. [ 123 ] Other structures such as microneedles with open microfluidic channels, [ 124 ] microfluidic modularized manufacturing, [ 125 ] printing microfluidic structures on surface‐functionalized polymer substrates, [ 126 ] and 3D parallelized microfluidic droplet generators and microfluidic for automation of sequential liquid control were all achieved by VP as well. [ 127 ] These structures are usually modularized, so they can be easily and freely recombined for other applications.…”

Fabrication of Microfluidic Devices for Emulsion Formation by Microstereolithography

“…Although the implementation of multimaterial 3D printing has been realized in other AM techniques (e.g., DIW [ 75 ], FDM [ 76 ], and jetting [ 77 ]), only a few solutions for resin-vat-based polymerization techniques (e.g., multimaterial projection micro-stereolithography (MM PµSL)) are known. In general, three different approaches have been developed: (I) vat switching [ 78 , 79 ], (II) in situ material exchange through dynamic fluid control [ 38 ], and (III) the assembly of pre-printed parts ( Figure 2 ) [ 80 , 81 , 82 ].…”

Biomimetic Vasculatures by 3D-Printed Porous Molds

“…The PEGDA parts were kept in 0.2 M CaCl2 solution at 4˚C until use. Before usage, the PEGDA parts were fitted into a two-part, 3D-printed rigid shell, as demonstrated in earlier works [37]. The two-part rigid shell functioned as a support frame around the soft PEGDA molds (Fig.…”

“…The SMC suspension was loaded into a 3 mL syringe and fitted with a 22G, blunt dispenser needle. After fabricating the vascular construct using the precursor bioink containing the SMCs as described in section 2.5 (Movie S4), the freestanding vascular construct was connected to a 3D printed frame and coupled to peristaltic pumps as described in our earlier work [37]. After seven days of culture under continuous perfusion culture at a flowrate of 2.2 µL•min -1 , the vascular construct was seeded with HUVECs.…”

“…These molds were 3D-printed as a two-part entity, with a negative cavity in the shape of the desired vascular network. As previously demonstrated using a digital light processing printer, we printed biomimetic vascular networks in PEGDA hydrogels [37].…”