Development of epoxy resin-based microfluidic devices using CO2 laser ablation for DNA amplification point-of-care (POC) applications

• Published in: International journal of advanced manufacturing technology Vol. 120; no. 7-8; pp. 4355 - 4372
• Main Authors: Mansour, Heba, Soliman, Emad A., El-Bab, Ahmed M. Fath, Abdel-Mawgood, Ahmed L.
• Format: Journal Article
• Language: English
• Published: London Springer London 01.06.2022; Springer Nature B.V
• Subjects: Ablation; Aspect ratio; CAE) and Design; Carbon dioxide; Carbon dioxide lasers; Cleanrooms; Computer-Aided Engineering (CAD; Engineering; Engraving; Epoxy resins; Feasibility studies; Fourier transforms; Gas chromatography; Heat affected zone; Industrial and Production Engineering; Infrared analysis; Laser ablation; Laser microscopy; Laser processing; Lasers; Machining; Manufacturing; Mass spectrometry; Mechanical Engineering; Media Management; Microchannels; Microfluidic devices; Original Article; Spectrum analysis; Surface roughness; Thermal stability; Thermogravimetric analysis; Microchannel dimensions; laser ablation; Micromachining; Epoxy-based chips; CO; Microchannel quality; Microfluidics
• DOI: 10.1007/s00170-022-08992-w
• ISSN: 0268-3768

Microfluidic devices are a rising technology to automatize chemical and biological operations. In this context, laser ablation has significant potential for polymer-based microfluidic platforms’ fast and economical manufacturing. Nevertheless, the manufacturing of epoxy-based microfluidic chips is considered highly cost full due to the demand for cleanroom facilities that utilize expensive equipment and lengthy processes. Therefore, this study targeted investigating the feasibility of epoxy resins to be fabricated as a lab-on-chip using carbon dioxide laser ablation. The chemical structural properties and thermal stability of the plain epoxy resins were characterized by Fourier transform infrared spectral analysis (FT-IR) and thermogravimetric analysis (TGA). Moreover, a specific migration test was performed to quantify potential migrants by gas chromatography coupled to mass spectrometry (GC–MS) to prove that the cured epoxy resin would not release unreacted monomers to the biological solution test, which caused inhibition of the sensitive biological reactions. By investigating the impact of this process on microchannels’ dimensions and quality, a laser technique using CO 2 laser was used in vector mode to engrave into a transparent epoxy resin chip. The resulting microchannels were characterized using 3D laser microscopy. The outcomes of this study showed considerable potential for laser ablation in machining the epoxy-based chips, whereas the microchannels machined by laser processing at an input power of 1.8 W and scanning speed of 5 mm/s have an aspect ratio of about 1.19 and a reasonable surface roughness (Ra) of ~ 15 µm. Meanwhile, the bulge height was 0.027 µm with no clogging, and HAZ was ~ 18 µm. This study validated the feasibility of quick and cost-effective CO 2 laser microfabrication to develop epoxy resin-based microfluidic chips without the need for cleanroom facilities that require expensive equipment and lengthy process.