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Open AccessFeature PaperCommunication
Micromachines 2018, 9(3), 125;

Digital Manufacturing of Selective Porous Barriers in Microchannels Using Multi-Material Stereolithography

Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
These authors contributed equally to this work.
Author to whom correspondence should be addressed.
Received: 1 February 2018 / Revised: 9 March 2018 / Accepted: 13 March 2018 / Published: 14 March 2018
(This article belongs to the Special Issue 3D Printed Microfluidic Devices)
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We have developed a sequential stereolithographic co-printing process using two different resins for fabricating porous barriers in microfluidic devices. We 3D-printed microfluidic channels with a resin made of poly(ethylene glycol) diacrylate (MW = 258) (PEG-DA-258), a UV photoinitiator, and a UV sensitizer. The porous barriers were created within the microchannels in a different resin made of either PEG-DA (MW = 575) (PEG-DA-575) or 40% (w/w in water) PEG-DA (MW = 700) (40% PEG-DA-700). We showed selective hydrogen ion diffusion across a 3D-printed PEG-DA-575 porous barrier in a cross-channel diffusion chip by observing color changes in phenol red, a pH indicator. We also demonstrated the diffusion of fluorescein across a 3D-printed 40% PEG-DA-700 porous barrier in a symmetric-channel diffusion chip by measuring fluorescence intensity changes across the porous barrier. Creating microfluidic chips with integrated porous barriers using a semi-automated 3D printing process shortens the design and processing time, avoids assembly and bonding complications, and reduces manufacturing costs compared to micromolding processes. We believe that our digital manufacturing method for fabricating selective porous barriers provides an inexpensive, simple, convenient and reproducible route to molecule delivery in the fields of molecular filtration and cell-based microdevices. View Full-Text
Keywords: multi-material stereolithography; porous barrier; diffusion; microfluidics multi-material stereolithography; porous barrier; diffusion; microfluidics

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Kim, Y.T.; Castro, K.; Bhattacharjee, N.; Folch, A. Digital Manufacturing of Selective Porous Barriers in Microchannels Using Multi-Material Stereolithography. Micromachines 2018, 9, 125.

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