Editing Microfluidics (section)

=== Open microfluidics ===
The behavior of fluids and their control in open microchannels came into focus around 2005<ref name="Melinvan der Wijngaart2005">{{cite journal | vauthors = Melin J, van der Wijngaart W, Stemme G | title = Behaviour and design considerations for continuous flow closed-open-closed liquid microchannels | journal = Lab on a Chip | volume = 5 | issue = 6 | pages = 682–686 | date = June 2005 | pmid = 15915262 | doi = 10.1039/b501781e | url = http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-14775 }}</ref> and applied in air-to-liquid sample collection<ref name="FriskRönnholm2006">{{cite journal | vauthors = Frisk T, Rönnholm D, van der Wijngaart W, Stemme G | title = A micromachined interface for airborne sample-to-liquid transfer and its application in a biosensor system | journal = Lab on a Chip | volume = 6 | issue = 12 | pages = 1504–1509 | date = December 2006 | pmid = 17203153 | doi = 10.1039/B612526N | url = http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-14188 }}</ref><ref name="FriskSandström2008">{{cite journal | vauthors = Frisk T, Sandström N, Eng L, van der Wijngaart W, Månsson P, Stemme G | title = An integrated QCM-based narcotics sensing microsystem | journal = Lab on a Chip | volume = 8 | issue = 10 | pages = 1648–1657 | date = October 2008 | pmid = 18813386 | doi = 10.1039/b800487k | url = http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-14189 }}</ref> and chromatography.<ref name="JacksénFrisk2007">{{cite journal | vauthors = Jacksén J, Frisk T, Redeby T, Parmar V, van der Wijngaart W, Stemme G, Emmer A | title = Off-line integration of CE and MALDI-MS using a closed-open-closed microchannel system | journal = Electrophoresis | volume = 28 | issue = 14 | pages = 2458–2465 | date = July 2007 | pmid = 17577881 | doi = 10.1002/elps.200600735 | s2cid = 16337938 | doi-access = free }}</ref> In [[open microfluidics]], at least one boundary of the system is removed, exposing the fluid to air or another interface (i.e. liquid).<ref name=":1">{{cite book| vauthors = Berthier J, Brakke KA, Berthier E |date=2016-08-01|title=Open Microfluidics|doi=10.1002/9781118720936|isbn=9781118720936}}</ref><ref>{{cite journal | vauthors = Pfohl T, Mugele F, Seemann R, Herminghaus S | title = Trends in microfluidics with complex fluids | journal = ChemPhysChem | volume = 4 | issue = 12 | pages = 1291–1298 | date = December 2003 | pmid = 14714376 | doi = 10.1002/cphc.200300847 | url = https://ris.utwente.nl/ws/files/6488126/trends_in_microfluidics.pdf }}</ref><ref name=":2">{{cite journal | vauthors = Kaigala GV, Lovchik RD, Delamarche E | title = Microfluidics in the "open space" for performing localized chemistry on biological interfaces | journal = Angewandte Chemie | volume = 51 | issue = 45 | pages = 11224–11240 | date = November 2012 | pmid = 23111955 | doi = 10.1002/anie.201201798 }}</ref> Advantages of open microfluidics include accessibility to the flowing liquid for intervention, larger liquid-gas surface area, and minimized bubble formation.<ref>{{cite journal |last1=Lade |first1=R. K. |last2=Jochem |first2=K. S. |last3=Macosko |first3=C. W. |last4=Francis |first4=L. F. |date=2018 |title=Capillary Coatings: Flow and Drying Dynamics in Open Microchannels |url=https://doi.org/10.1021/acs.langmuir.8b00811 |journal=Langmuir |volume=34 |issue=26 |pages=7624–7639 | pmid=29787270 | doi=10.1021/acs.langmuir.8b00811}}</ref><ref name=":1" /><ref name=":2" /><ref>{{cite journal | vauthors = Li C, Boban M, Tuteja A | title = Open-channel, water-in-oil emulsification in paper-based microfluidic devices | journal = Lab on a Chip | volume = 17 | issue = 8 | pages = 1436–1441 | date = April 2017 | pmid = 28322402 | doi = 10.1039/c7lc00114b | s2cid = 5046916 }}</ref>  Another advantage of open microfluidics is the ability to integrate open systems with surface-tension driven fluid flow, which eliminates the need for external pumping methods such as peristaltic or syringe pumps.<ref name=":4">{{cite journal | vauthors = Casavant BP, Berthier E, Theberge AB, Berthier J, Montanez-Sauri SI, Bischel LL, Brakke K, Hedman CJ, Bushman W, Keller NP, Beebe DJ | display-authors = 6 | title = Suspended microfluidics | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 110 | issue = 25 | pages = 10111–10116 | date = June 2013 | pmid = 23729815 | pmc = 3690848 | doi = 10.1073/pnas.1302566110 | doi-access = free | bibcode = 2013PNAS..11010111C }}</ref> Open microfluidic devices are also easy and inexpensive to fabricate by milling, thermoforming, and hot embossing.<ref>{{cite journal | vauthors = Guckenberger DJ, de Groot TE, Wan AM, Beebe DJ, Young EW | title = Micromilling: a method for ultra-rapid prototyping of plastic microfluidic devices | journal = Lab on a Chip | volume = 15 | issue = 11 | pages = 2364–2378 | date = June 2015 | pmid = 25906246 | pmc = 4439323 | doi = 10.1039/c5lc00234f }}</ref><ref>{{cite journal|vauthors = Truckenmüller R, Rummler Z, Schaller T, Schomburg WK|date=2002-06-13|title=Low-cost thermoforming of micro fluidic analysis chips|journal=Journal of Micromechanics and Microengineering|volume=12|issue=4|pages=375–379|doi=10.1088/0960-1317/12/4/304|issn=0960-1317|bibcode=2002JMiMi..12..375T|s2cid=250860338 }}</ref><ref>{{cite journal | vauthors = Jeon JS, Chung S, Kamm RD, Charest JL | title = Hot embossing for fabrication of a microfluidic 3D cell culture platform | journal = Biomedical Microdevices | volume = 13 | issue = 2 | pages = 325–333 | date = April 2011 | pmid = 21113663 | pmc = 3117225 | doi = 10.1007/s10544-010-9496-0 }}</ref><ref>{{cite journal | vauthors = Young EW, Berthier E, Guckenberger DJ, Sackmann E, Lamers C, Meyvantsson I, Huttenlocher A, Beebe DJ | display-authors = 6 | title = Rapid prototyping of arrayed microfluidic systems in polystyrene for cell-based assays | journal = Analytical Chemistry | volume = 83 | issue = 4 | pages = 1408–1417 | date = February 2011 | pmid = 21261280 | pmc = 3052265 | doi = 10.1021/ac102897h }}</ref> In addition, open microfluidics eliminates the need to glue or bond a cover for devices, which could be detrimental to capillary flows. Examples of open microfluidics include open-channel microfluidics, rail-based microfluidics, [[Paper-based microfluidics|paper-based]], and thread-based microfluidics.<ref name=":1" /><ref name=":4" /><ref>{{cite journal | vauthors = Bouaidat S, Hansen O, Bruus H, Berendsen C, Bau-Madsen NK, Thomsen P, Wolff A, Jonsmann J | display-authors = 6 | title = Surface-directed capillary system; theory, experiments and applications | journal = Lab on a Chip | volume = 5 | issue = 8 | pages = 827–836 | date = August 2005 | pmid = 16027933 | doi = 10.1039/b502207j | s2cid = 18125405 }}</ref>  Disadvantages to open systems include susceptibility to evaporation,<ref>{{cite journal | vauthors = Kachel S, Zhou Y, Scharfer P, Vrančić C, Petrich W, Schabel W | title = Evaporation from open microchannel grooves | journal = Lab on a Chip | volume = 14 | issue = 4 | pages = 771–778 | date = February 2014 | pmid = 24345870 | doi = 10.1039/c3lc50892g }}</ref> contamination,<ref>{{cite book | vauthors = Ogawa M, Higashi K, Miki N | title = 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)| chapter = Development of hydrogel microtubes for microbe culture in open environment | volume = 2015 | issue = 6 | pages = 5896–5899 | date = August 2015 | pmid =  26737633 | pmc =  | doi = 10.1109/EMBC.2015.7319733 | isbn = 978-1-4244-9271-8| s2cid = 4089852}}</ref> and limited flow rate.<ref name=":2" />