Editing Digital microfluidics (section)

== Implementation ==

In one of various embodiments of EWOD-based microfluidic biochips, investigated first by [[Cytonix]] in 1987 [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] {{Webarchive|url=https://web.archive.org/web/20200919134752/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 |date=2020-09-19 }} and subsequently commercialized by Advanced Liquid Logic, there are two parallel glass plates. The bottom plate contains a patterned array of individually controllable [[electrodes]] and the top plate is coated with a continuous [[Ground (electricity)|grounding electrode]]. A [[dielectric]] [[Electrical insulation|insulator]] coated with a [[hydrophobic]] is added to the plates to decrease the wet-ability of the surface and to add [[capacitance]] between the droplet and the control electrode. The droplet containing biochemical samples and the filler medium, such as the [[silicone oil]], a fluorinated oil, or air, are sandwiched between the plates and the droplets travel inside the filler medium. In order to move a [[droplet]], a control [[voltage]] is applied to an [[electrode]] adjacent to the droplet, and at the same time, the electrode just  under the droplet is deactivated. By varying the [[electric potential]] along a linear array of electrodes, [[electrowetting]] can be used to move droplets along this line of electrodes.