Stereolithography 3D printing method for multi-material hydrogel 2D photo-patterning in a microfluidic chip

Abstract

We present a novel and straightforward method using a standard stereolithography (SLA) 3D printer for high-resolution (20 μm x-y resolution), multi-material 2D hydrogel photo-patterning directly within a microfluidic chip. The process involves sequential injections of photosensitive hydrogel into a transparent microfluidic chip coupled with sequential direct laser writing by the printer through point-by-point photopolymerization. Our approach integrates a custom miniaturized syringe pump system into the SLA printer, thereby enabling fluid management and sequential injection of different photosensitive hydrogels directly into the microfluidic environment between each laser writing sequence. This technique enables the fabrication of intricate, multi-material hydrogel patterns (e.g., PEGDA and HAMA) with high spatial resolution over areas spanning several square millimeters. Future developments will focus on expanding the range of biomaterials and incorporating cell-laden hydrogels to facilitate the creation of biologically relevant microenvironments on chip.

This study opens new possibilities for high-resolution, multi-material hydrogel patterning in microfluidics and offers a valuable platform for advancing research in microsystems engineering.