{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,6]],"date-time":"2026-09-06T05:12:44Z","timestamp":1788671564441,"version":"build-2803163510"},"reference-count":22,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T00:00:00Z","timestamp":1777334400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["2245494"],"award-info":[{"award-number":["2245494"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["2140148"],"award-info":[{"award-number":["2140148"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"award":["2245494"],"award-info":[{"award-number":["2245494"]}],"id":[{"id":"https:\/\/ror.org\/021nxhr62","id-type":"ROR","asserted-by":"publisher"}]},{"award":["2140148"],"award-info":[{"award-number":["2140148"]}],"id":[{"id":"https:\/\/ror.org\/021nxhr62","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R15GM123405"],"award-info":[{"award-number":["R15GM123405"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"award":["R15GM123405"],"award-info":[{"award-number":["R15GM123405"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Post-processing remains a major bottleneck in the fabrication of microfluidic devices using Digital Light Processing Stereolithography (DLP-SLA) 3D printing, where unpolymerized resin trapped within internal structures must be removed without damaging delicate features such as thin membranes, valves, and pumps. Manual flushing is slow, inconsistent, and prone to structural failure, especially as device complexity and port counts increase. Here, we present the first fully automated flushing system for DLP-SLA microfluidic devices, enabled by a standardized chip-to-chip (C2C) interconnect architecture and an electronically controlled pneumatic routing platform. A reusable 32-port flushing interface chip provides alignment, sealing, and modular coupling to arbitrary device chips through integrated microgaskets, while a network of electronic pressure controllers, differential pressure sensors, and multi-port rotary valves enable precise, programmable application of pressure, vacuum, and solvent conditions. We introduce a fluidic-circuit model of the system that relates applied pressure to the pressure drop across device structures and experimentally validate this model using channels with varying fluidic resistances. Using this platform, we demonstrate robust flushing of both passive (straight and serpentine channels) and active (valves, pumps) microfluidic elements, as well as application-specific devices including mixers and concentration-gradient generators. Our system eliminates manual handling, improves valve membrane survival, and provides repeatable flushing across a broad range of device geometries. This work establishes a scalable foundation for automated post-processing in 3D-printed microfluidics and significantly advances the practicality of DLP-SLA fabrication for complex, multi-layered microfluidic devices.<\/jats:p>","DOI":"10.3390\/mi17050538","type":"journal-article","created":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T09:46:11Z","timestamp":1777455971000},"page":"538","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Automated Flushing System for Post-Processing in Microfluidic Device Fabrication"],"prefix":"10.3390","volume":"17","author":[{"given":"Sebastian","family":"Zapata","sequence":"first","affiliation":[{"name":"Electrical and Computer Engineering Department, Brigham Young University, Provo, UT 84602, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brady","family":"Goenner","sequence":"additional","affiliation":[{"name":"Mechanical Engineering Department, University of Utah, Salt Lake City, UT 84112, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-3606-3965","authenticated-orcid":false,"given":"Dallin S.","family":"Miner","sequence":"additional","affiliation":[{"name":"Electrical and Computer Engineering Department, Brigham Young University, Provo, UT 84602, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5843-3464","authenticated-orcid":false,"given":"Bruce K.","family":"Gale","sequence":"additional","affiliation":[{"name":"Mechanical Engineering Department, University of Utah, Salt Lake City, UT 84112, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7241-5764","authenticated-orcid":false,"given":"Gregory P.","family":"Nordin","sequence":"additional","affiliation":[{"name":"Electrical and Computer Engineering Department, Brigham Young University, Provo, UT 84602, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1038\/nature05058","article-title":"The origins and the future of microfluidics","volume":"442","author":"Whitesides","year":"2006","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3240","DOI":"10.1021\/ac403397r","article-title":"Evaluation of 3d printing and its potential impact on biotechnology and the chemical sciences","volume":"86","author":"Gross","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2202","DOI":"10.1039\/D4LC00014E","article-title":"Integrated biocompatible 3D printed isoporous membranes with 7 \u03bcm pores","volume":"24","author":"Viglione","year":"2024","journal-title":"Lab. Chip"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3537","DOI":"10.1039\/D3LC00094J","article-title":"Vat photopolymerization 3D printed microfluidic devices for organ-on-a-chip applications","volume":"23","author":"Milton","year":"2023","journal-title":"Lab. Chip"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1934","DOI":"10.1039\/C5LC00126A","article-title":"3d printed microfluidic automation","volume":"15","author":"Au","year":"2015","journal-title":"Lab. Chip"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1993","DOI":"10.1039\/C6LC00284F","article-title":"3d printed microfluidic devices: Enablers and barriers","volume":"16","author":"Waheed","year":"2016","journal-title":"Lab. Chip"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"12322","DOI":"10.1021\/acs.analchem.0c01970","article-title":"3D printed microfluidic devices for solid-phase extraction and on-chip fluorescent labeling of preterm birth risk biomarkers","volume":"92","author":"Bickham","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1800395","DOI":"10.1002\/admt.201800395","article-title":"High-precision stereolithography of biomicrofluidic devices","volume":"4","author":"Kuo","year":"2019","journal-title":"Adv. Mater. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1146\/annurev-anchem-091619-102649","article-title":"3d printed microfluidics","volume":"13","author":"Nielsen","year":"2020","journal-title":"Annu. Rev. Anal. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1063\/1.4905840","article-title":"3d printed microfluidic devices with integrated valves","volume":"9","author":"Rogers","year":"2015","journal-title":"Biomicrofluidics"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2899","DOI":"10.1039\/C7LC00644F","article-title":"Custom 3d printer and resin for 18 \u03bcm \u00d7 20\u03bcm microfluidic flow channels","volume":"17","author":"Gong","year":"2017","journal-title":"Lab. Chip"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5509","DOI":"10.1038\/s41467-021-25788-w","article-title":"Spatially and optically tailored 3D printing for highly miniaturized and integrated microfluidics","volume":"12","author":"Chartrand","year":"2021","journal-title":"Nat. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2450","DOI":"10.1039\/C6LC00565A","article-title":"High density 3d printed microfluidic valves, pumps, and multiplexers","volume":"16","author":"Gong","year":"2016","journal-title":"Lab. Chip"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"106621","DOI":"10.1039\/C5RA23855B","article-title":"Optical approach to resin formulation for 3d printed microfluidics","volume":"5","author":"Gong","year":"2015","journal-title":"RSC Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1039\/C7LC01113J","article-title":"3d printed high density, reversible, chip-to-chip microfluidic interconnects","volume":"18","author":"Gong","year":"2018","journal-title":"Lab. Chip"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1039\/C2LC20799K","article-title":"Design of pressure-driven microfluidic networks using electric circuit analogy","volume":"12","author":"Oh","year":"2012","journal-title":"Lab. Chip"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1016\/j.crhy.2004.02.012","article-title":"Steady flows in networks of microfluidic channels: Building on the analogy with electrical circuits","volume":"5","author":"Ajdari","year":"2004","journal-title":"Comptes Rendus Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3311","DOI":"10.1039\/D3LC00265A","article-title":"Hydraulic\u2013electric analogy for design and operation of microfluidic systems","volume":"23","author":"Li","year":"2023","journal-title":"Lab. Chip"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1119\/10.0003395","article-title":"Tesla\u2019s fluidic diode and the electronic\u2013hydraulic analogy","volume":"89","author":"Nguyen","year":"2021","journal-title":"Am. J. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Rousset, N., Lohasz, C., Boos, J.A., Misun, P.M., Cardes, F., and Hierlemann, A. (2022). Circuit-based design of microfluidic drop networks. Micromachines, 13.","DOI":"10.3390\/mi13071124"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"33077","DOI":"10.1038\/s41598-025-15976-9","article-title":"An open source platform to automate the design, verification, and manufacture of 3D printed microfluidic devices","volume":"15","author":"Goenner","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Boaks, M., Roper, C., Viglione, M., Hooper, K., Woolley, A.T., Christensen, K.A., and Nordin, G.P. (2023). Biocompatible high-resolution 3D-printed microfluidic devices: Integrated cell chemotaxis demonstration. Micromachines, 14.","DOI":"10.3390\/mi14081589"}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/5\/538\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T10:10:24Z","timestamp":1777457424000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/5\/538"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,28]]},"references-count":22,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["mi17050538"],"URL":"https:\/\/doi.org\/10.3390\/mi17050538","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,28]]}}}