Microsized 3D Hydrogel Printing System using Microfluidic Maskless Lithography and Single Axis Stepper Motor

The 3D printing apparatus in conventional inkjet and stereolithography systems is limited to continuous fabrication of a microsized three-dimensional hydrogel composed of multiple substances. We present a micro three-dimensional printing system by combining a polydimethylsiloxane microfluidic channel through which various fluids can flow into a micro two-dimensional particle generation system, and a single-axis stepper motor to control the thickness of each layer. The optimal channel designs for micro three-dimensional printing were set up through a physics simulation program and using the simulation analysis, the optimal microfluidic channel was fabricated. Through the system and channel, three-dimensional micropatterns and particles could be fabricated and the generated microparticles automatically collected by the washing flow in the channel. Zinc oxide nanoparticle materials transparent, biocompatible, and capable of absorbing ultraviolet light were added to the premixed photocurable solution used for the microparticle production, and thereby precise micro three-dimensional patterns and particles could be fabricated. In addition, by transporting a variety of fluids into the microfluidic channel, it was possible to create micro three-dimensional particles composed of heterogeneous materials.