{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,22]],"date-time":"2025-10-22T17:52:50Z","timestamp":1761155570281,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2012,3,29]],"date-time":"2012-03-29T00:00:00Z","timestamp":1332979200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>This paper presents an integrated digitally controllable microfluidic system for continuous solution supply with a real-time concentration control. This system contains multiple independently operating mixing modules, each integrated with two vortex micropumps, two Tesla valves and a micromixer. The interior surface of the system is made of biocompatible materials using a polymer micro-fabrication process and thus its operation can be applied to chemicals and bio-reagents. In each module, pumping of fluid is achieved by the vortex micropump working with the rotation of a micro-impeller. The downstream fluid mixing is based on mechanical vibrations driven by a lead zirconate titanate ceramic diaphragm actuator located below the mixing chamber. We have conducted experiments to prove that the addition of the micro-pillar structures to the mixing chamber further improves the mixing performance. We also developed a computer-controlled automated driver system to control the real-time fluid mixing and concentration regulation with the mixing module array. This research demonstrates the integration of digitally controllable polymer-based microfluidic modules as a fully functional system, which has great potential in the automation of many bio-fluid handling processes in bio-related applications.<\/jats:p>","DOI":"10.3390\/mi3020279","type":"journal-article","created":{"date-parts":[[2012,3,29]],"date-time":"2012-03-29T06:44:51Z","timestamp":1333003491000},"page":"279-294","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["A Digitally Controllable Polymer-Based Microfluidic Mixing Module Array"],"prefix":"10.3390","volume":"3","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5188-3830","authenticated-orcid":false,"given":"Raymond H. W.","family":"Lam","sequence":"first","affiliation":[{"name":"Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wen J.","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2012,3,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1126\/science.261.5123.895","article-title":"Micromachining a miniaturized capillary electrophoresis-based chemical analysis system on a chip","volume":"261","author":"Harrison","year":"1993","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1126\/science.1076996","article-title":"Microfluidic large-scale integration","volume":"298","author":"Thorsen","year":"2002","journal-title":"Science"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1146\/annurev.biophys.36.040306.132646","article-title":"Microfluidic large-scale integration: The evolution of design rules for biological automation","volume":"36","author":"Melin","year":"2007","journal-title":"Annu. 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