Rapid Prototyping of High-resolution Large Format Microfluidic Device Through Maskless Image Guided In-situ Photopolymerization

Abstract

Microfluidic devices have been widely used in mechanical, biomedical, chemical, and materials research. As a result, it is becoming increasingly important to have a cheap, fast, and reliable method for rapid microfabrication. However, prototyping of microfluidic devices typically suffers from the high initial cost, low resolution, rough surface finish, and long turn-around time. Here we present a strategic approach to closed-loop control of deterministic fabrication process based on in-situ image analysis called image-guided in-situ maskless lithography (IGIs-ML). Using the closed-loop control along with flush-flow functionality and leveraging the swelling behavior of the photocurable polymer, we demonstrate the fabrication of sub-micron high aspect ratio channels (800 nm width and >10 µm height) close to the light diffraction limit. This outperforms any reported rapid prototyping platforms which can typically reach tens of µm in channel width. Such dimensional capability is even comparable to some of the most advanced fabrication methods currently available. Dynamic image analysis simultaneously provides superior repeatability of densely packed patterns across a large area and multiple devices. A general and robust approach is established to fabricate a wide variety of microfluidic devices. This resolves the critical over-curing issues and size limitations in rapid prototyping of microfluidic devices, enabling affordable and reliable exploration of design space beyond the resolution of traditional photolithography.

Research on the large-format splicing method for stamping-type digital light processing 3D printing

“…Lin Chunbo and others designed a dynamic projection scanning 3D printing exposure system, realizing two-dimensional directional scanning exposure, namely, a printing method where lines form surfaces [25]. By intermittently displaying maskless images through Digital Micromirror Device (DMD), the 3D printing of large-area microfluidic devices has been achieved [26]. Ha and others demonstrated a step-andrepeat technique.…”