Jump to main content
Jump to site search

Issue 17, 2017
Previous Article Next Article

Custom 3D printer and resin for 18 μm × 20 μm microfluidic flow channels

Author affiliations

Abstract

While there is great interest in 3D printing for microfluidic device fabrication, to-date the achieved feature sizes have not been in the truly microfluidic regime (<100 μm). In this paper we demonstrate that a custom digital light processor stereolithographic (DLP-SLA) 3D printer and a specifically-designed, low cost, custom resin can readily achieve flow channel cross sections as small as 18 μm × 20 μm. Our 3D printer has a projected image plane resolution of 7.6 μm and uses a 385 nm LED, which dramatically increases the available selection of UV absorbers for resin formulation compared to 3D printers with 405 nm LEDs. Beginning with 20 candidate absorbers, we demonstrate the evaluation criteria and process flow required to develop a high-resolution resin. In doing so, we introduce a new mathematical model for characterizing the resin optical penetration depth based only on measurement of the absorber's molar absorptivity. Our final resin formulation uses 2-nitrophenyl phenyl sulfide (NPS) as the UV absorber. We also develop a novel channel narrowing technique that, together with the new resin and 3D printer resolution, enables small flow channel fabrication. We demonstrate the efficacy of our approach by fabricating 3D serpentine flow channels 41 mm long in a volume of only 0.12 mm3, and by printing high aspect ratio flow channels <25 μm wide and 3 mm tall. These results indicate that 3D printing is finally positioned to challenge the pre-eminence of methods such as soft lithography for microfluidic device prototyping and fabrication.

Graphical abstract: Custom 3D printer and resin for 18 μm × 20 μm microfluidic flow channels

Back to tab navigation

Supplementary files

Publication details

The article was received on 20 Jun 2017, accepted on 13 Jul 2017 and first published on 14 Jul 2017


Article type: Paper
DOI: 10.1039/C7LC00644F
Citation: Lab Chip, 2017,17, 2899-2909
  •   Request permissions

    Custom 3D printer and resin for 18 μm × 20 μm microfluidic flow channels

    H. Gong, B. P. Bickham, A. T. Woolley and G. P. Nordin, Lab Chip, 2017, 17, 2899
    DOI: 10.1039/C7LC00644F

Search articles by author

Spotlight

Advertisements