Editing Microfluidics (section)

===Digital microfluidics===

{{Main|Digital microfluidics}}
Alternatives to the above closed-channel continuous-flow systems include novel open structures, where discrete, independently controllable droplets
are manipulated on a substrate using [[electrowetting]]. Following the analogy of digital microelectronics, this approach is referred to as [[digital microfluidics]]. Le Pesant et al. pioneered the use of electrocapillary forces to move droplets on a digital track.<ref>Le Pesant et al., Electrodes for a device operating by electrically controlled fluid displacement, [https://worldwide.espacenet.com/patent/search/family/009290366/publication/US4569575A?q=pn%3DUS4569575 U.S. Pat. No. 4,569,575], Feb. 11, 1986.</ref> The "fluid transistor" pioneered by Cytonix<ref>[https://www.nsf.gov/awardsearch/piSearch.do;jsessionid=D05E82394F781CBA17DB0C5AC8E3C0B8?SearchType=piSearch&page=1&QueryText=&PIFirstName=james&PILastName=brown&PIInstitution=cytonix&PIState=MD&PIZip=&PICountry=US&RestrictExpired=on&Search=Search#results NSF Award Search: Advanced Search Results<!-- Bot generated title -->]</ref> also played a role. The technology was subsequently commercialised by Duke University. By using discrete unit-volume droplets,<ref name="droplet microfluidics">{{cite journal|vauthors = Chokkalingam V, Herminghaus S, Seemann R|year = 2008|title = Self-synchronizing Pairwise Production of Monodisperse Droplets by Microfluidic Step Emulsification|url = http://apl.aip.org/applab/v93/i25/p254101_s1|journal = Applied Physics Letters|volume = 93|issue =  25|page = 254101|doi = 10.1063/1.3050461|bibcode = 2008ApPhL..93y4101C|url-status = dead|archive-url = https://archive.today/20130113004540/http://apl.aip.org/applab/v93/i25/p254101_s1|archive-date = 2013-01-13 }}</ref>  a microfluidic function can be reduced to a set of repeated basic operations, i.e., moving one unit of fluid over one unit of distance. This "digitisation" method facilitates the use of a hierarchical and cell-based approach for microfluidic biochip design. Therefore, digital microfluidics offers a flexible and scalable system architecture as well as high [[fault-tolerance]] capability. Moreover, because each droplet can be controlled independently, these systems also have dynamic reconfigurability, whereby groups of unit cells in a microfluidic array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. Although droplets are manipulated in confined microfluidic channels, since the control on droplets is not independent, it should not be confused as "digital microfluidics". One common actuation method for digital microfluidics is [[electrowetting]]-on-dielectric ([[EWOD]]).<ref>{{cite journal| vauthors = Lee J, Kim CJ |s2cid=25996316|date=June 2000|title=Surface-tension-driven microactuation based on continuous electrowetting|journal=Journal of Microelectromechanical Systems|volume=9|issue=2|pages=171–180|doi=10.1109/84.846697|issn=1057-7157}}</ref> Many lab-on-a-chip applications have been demonstrated within the digital microfluidics paradigm using electrowetting.