3D Printed Tooling for Injection Molded Microfluidics

Abstract

Microfluidics have been used for several decades to conduct a wide range of research in chemistry and the life sciences. The reduced dimensions of these devices give them advantages over classical analysis techniques such as increased sensitivity, shorter analysis times, and lower reagent consumption. However, current manufacturing processes for microfluidic chips either limit them to materials with unwanted properties, or are not cost‐effective for rapid‐prototyping approaches. Here the authors show that inlays for injection moulding can be 3D printed, thus reducing the skills, cost, and time required for tool fabrication. They demonstrate the importance of orientation of the part during 3D printing so that features as small as 100 × 200 µm can be printed. They also demonstrate that the 3D printed inlay is durable enough to fabricate at least 500 parts. Furthermore, devices can be designed, manufactured, and tested within one working day. Finally, as demonstrators they design and mould a microfluidic chip to house a plasmonic biosensor as well as a device to house liver organoids showing how such chips can be used in organ‐on‐a‐chip applications. This new fabrication technique bridges the gap between small production and industrial scale manufacturing, while making microfluidics cheaper, and more widely accessible.

3D Printing and Rapid Replication of Advanced Numerically Generated Rough Surface Topographies in Numerous Polymers

“…Typically, industrial production runs would be far longer, reaching hundreds of components. Convery et al [ 33 ] confirmed that an inlay of the same 3D‐printed material will not suffer significant degradation even after 500 parts are fabricated using the inlay for an injection molding run. They found that the micro‐channels in their designs were still within acceptable error margins even after 500 parts were produced.…”

“…There are a significant number of variables that can influence the replication quality of the molding cycle including injection velocity, holding time and pressure, tooling temperature, etc. [20,32,33,36] These all have individual influence over the quality of replication; therefore, it would seem reasonable that the parameters will not have been optimally tuned to facilitate the best replication possible for these rough surface topographies. Non-optimum molding parameters can lead to incomplete filling of the mold and poor replication.…”

Biomedical Applications of Microfluidic Devices: A Review

“…Lee et al [ 146 ] discussed advantages and limitations of rapid injection molding and provided design recommendations to successfully utilize this method for microscale cell-based assay development. Convery et al [ 147 ] showed that inlays for injection molding could be three-dimensionally printed. Generally, the main drawbacks of microinjection molding are material restrictions related to thermoplastics and mold expensive fabrication and limited resolution [ 25 , 137 ].…”

Digital manufacturing for accelerating organ-on-a-chip dissemination and electrochemical biosensing integration

“…26 Furthermore, DM technologies could be employed in either direct writing mode to pattern fully functional devices directly on the substrate, or to create micromoulds for polymer casting in a similar way to soft lithography and injection moulding. 27 In this way, those groups experienced in soft lithography can incorporate all the advantages of DM direct writing modes while maintaining the option to make alternative micromoulds for PDMS casting (Fig. 2, interchange between master mould and DM stations).…”