Hydrophilic silicone-based ink derived from amphiphilic siloxane oligomers for the vat photopolymerization printing of embedded-channel fluidic devices

Abstract

The emergence of vat photopolymerization (VP) printing as an alternative fabrication method for fluidic devices has led to the rapid development of silicone-based resin material. However, most silicone-based resin materials are hydrophobic in nature, rendering them unsuitable for biomedical applications without post-processing. Herein, we introduce a new type of hydrophilic silicone-based resin material derived from vinyl-terminated amphiphilic siloxane oligomers, acrylamide, and glycidyl methacrylate, for the printing of fluidic devices. We demonstrate the strategy to overcome the challenges associated with amphiphilic-based formulation by adjusting the amphiphilic siloxane oligomer conformation with appropriate solvent blend, resulting in a silicone-based resin material with low pre-gel viscosity, high transparency, and hydrophilic characteristics. Besides, the developed material exhibits tunable elastic properties, excellent polar solvent resistance, and good biocompatibility. Upon photocuring depth tuning, the developed material displays high printing accuracy down to 200 µm in width and 50 µm in height. The material’s ability to replicate embedded fluidic channels with diverse shapes in one-step printing further shows its potential for fluidic device fabrication. The printed devices were revealed to be highly functional with the capability to process fluid at an elevated temperature of up to 100 ºC for 24 hours and a continuous flow rate of up to 20 mL/min. Further demonstration of the hydrogel beads synthesis for drug encapsulation reveals the feasibility of the printed device for real-world biomedical applications. The successful VP printing of hydrophilic silicone-based embedded-channel fluidic devices opened up new avenues for the fabrication of silicone-based fluidic devices for biomedical applications.