Fabrication of Hard–Soft Microfluidic Devices Using Hybrid 3D Printing

Abstract

Widely accessible, inexpensive, easy-to-use consumer 3D printers, such as desktop stereolithography (SLA) and fused-deposition modeling (FDM) systems are increasingly employed in prototyping and customizing miniaturized fluidic systems for diagnostics and research. However, these 3D printers are generally limited to printing parts made of only one material type, which limits the functionality of the microfluidic devices without additional assembly and bonding steps. Moreover, mating of different materials requires good sealing in such microfluidic devices. Here, we report methods to print hybrid structures comprising a hard, rigid component (clear polymethacrylate polymer) printed by a low-cost SLA printer, and where the first printed part is accurately mated and adhered to a second, soft, flexible component (thermoplastic polyurethane elastomer) printed by an FDM printer. The prescribed mounting and alignment of the first-printed SLA-printed hard component, and its pre-treatment and heating during the second FDM step, can produce leak-free bonds at material interfaces. To demonstrate the utility of such hybrid 3D-printing, we prototype and test three components: i) finger-actuated pump, ii) quick-connect fluid coupler, and iii) nucleic acid amplification test device with screw-type twist sealing for sample introduction.

3D-Printed Microfluidics and Potential Biomedical Applications

“…The intuitive design of device operation can be particularly useful for self-governing point-of-care research that reduces the burden on laboratory or healthcare systems during periods of need, such as the COVID-19 pandemic or other global health crises. Ruiz et al defined a two-stage 3D printing process for the development of hybrid microfluidic devices integrating both hard and soft materials by using lowcost 3D consumer printers (Ruiz et al, 2020). Printed hard components are first created by a stereolithography (SLA) printer moved to a second FDM printer where a soft printed part is connected to the FDM printing.…”

Microfluidic chip fabrication and performance analysis of 3D printed material for use in microfluidic nucleic acid amplification applications

“…However, similar approaches with sacrificial material has not been seen for the lower-cost DLP SLA. Different approaches to print enclosed microfluidics with DLP SLA [46,50,51] have produced successful results in their field of applications, however the main drawback lies on the use of adhesives sheets that introduce material inconsistency in the channels and impose multi-step processing.…”

The Field Guide to 3D Printing in Microscopy

“…However, multiplexers allow control over multiple valves employing only a few control channels, thus facilitating the upscaling of designs and adaptation into highly compact and complex microfluidic systems (56). Microfluidic chips can work as sensors, detecting physical and chemical changes inside chambers by measuring volumes on the picoliter scale (62)(63)(64)(65).…”