Rapid prototyping method for 3D PDMS microfluidic devices using a red femtosecond laser

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Abstract

A rapid prototyping technique is demonstrated which uses a red femtosecond laser to produce a metallic mould which is then directly used for the replica moulding of PDMS. The manufacturing process can be completed in less than 6 h making it a viable technique for testing new designs quickly. The technique is validated by creating a microfluidic device with channels of height and depth of 300 µm, with a ramp test structure where the height and width of the channels reduces to 100 µm to demonstrate the techniques 3D capabilities. The resulting PDMS device was easily removed from the metallic mould and closely replicated the shape aside the expected shrinkage during thermal curing. As the technique uses a single replica process, the surface roughness at the base of the channels corresponds to the un-ablated polished metal mould, resulting in a very low surface roughness of 0.361 nm. The ablated metallic mould surface corresponds to the top of the PDMS device, which is bonded to glass and does not affect the flow within the channels, reducing the need for optimisation of laser parameters. Finally, the device is validated by demonstrating laminar flow with the no-slip condition.

Bibliographic note

Funding Information: The authors wish to thank with appreciation the laser-based manufacturing research group within the Advanced [M]anufacturing Technology Centre, Department of Mechanical Engineering, University of Birmingham, for the support provided in the manufacturing realisation aspects of this research. The author(s) received no financial support for the research, authorship, and/or publication of this article.

Details

Original languageEnglish
Pages (from-to)1-12
JournalAdvances in Mechanical Engineering
Volume12
Issue number12
Early online date17 Dec 2020
Publication statusPublished - Dec 2020

Keywords

  • 3D microfluidic chip, laser, lithography, Microfluidics, micromanufacture, rapid prototyping

ASJC Scopus subject areas