Editing Digital microfluidics (section)

=== From a reservoir ===
Creating a new droplet from a reservoir of liquid can be done in a similar fashion to splitting a droplet. In this case, the reservoir remains stationary while a sequence of electrodes are used to draw liquid out of the reservoir. This drawn liquid and the reservoir form a neck of liquid, akin to the neck of a splitting droplet but longer, and the collapsing of this neck forms a dispensed droplet from the drawn liquid.<ref name="Cho_2003" /><ref>{{Cite book| vauthors = Fan SK, Hashi C, Kim CJ |title=The Sixteenth Annual International Conference on Micro Electro Mechanical Systems, 2003. MEMS-03 Kyoto. IEEE |chapter=Manipulation of multiple droplets on N×M grid by cross-reference EWOD driving scheme and pressure-contact packaging |date=2003|pages=694–697|doi=10.1109/MEMSYS.2003.1189844|isbn=0-7803-7744-3 |s2cid=108612930}}</ref> In contrast to splitting, though, dispensing droplets in this manner is inconsistent in scale and results. There is no reliable distance liquid will need to be pulled from the reservoir for the neck to collapse, if it even collapses at all.<ref name="Elvira_2012">{{cite journal | vauthors = Elvira KS, Leatherbarrow R, Edel J, Demello A | title = Droplet dispensing in digital microfluidic devices: Assessment of long-term reproducibility | journal = Biomicrofluidics | volume = 6 | issue = 2 | pages = 22003–2200310 | date = June 2012 | pmid = 22655007 | pmc = 3360711 | doi = 10.1063/1.3693592 }}</ref> Because this distance varies, the volumes of dispensed droplets will also vary within the same device.<ref name="Elvira_2012" />

Due to these inconsistencies, alternative techniques for dispensing droplets have been used and proposed, including drawing liquid out of reservoirs in geometries that force a thinner neck,<ref name="Cho_2003" /><ref name="Nikapitiya_2014">{{Cite book | vauthors = Nikapitiya NJ, You SM, Moon H |title=2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS) |chapter=Droplet dispensing and splitting by electrowetting on dielectric digital microfluidics |date=2014|pages=955–958|doi=10.1109/MEMSYS.2014.6765801 |isbn=978-1-4799-3509-3|s2cid=45003766}}</ref> using a continuous and replenishable electrowetting channel,<ref name="Liu_2014"/> and moving reservoirs into corners so as to cut the reservoir down the middle.<ref name="Teh_2008" /><ref name="Nikapitiya_2014" /> Multiple iterations of the latter can produce droplets of more manageable sizes.