US 12,472,502 B2
Oil residue protection in oil-encapsulated digital microfluidics
Daniel Brassard, Longueuil (CA); Lidija Malic, Saint Leonard (CA); Keith Morton, St-Bruno (CA); and Teodor Veres, Montreal (CA)
Assigned to National Research Council of Canada, Ottawa (CA)
Appl. No. 17/618,037
Filed by National Research Council of Canada, Ottawa (CA)
PCT Filed Jul. 9, 2020, PCT No. PCT/IB2020/056483
§ 371(c)(1), (2) Date Dec. 10, 2021,
PCT Pub. No. WO2021/005560, PCT Pub. Date Jan. 14, 2021.
Claims priority of provisional application 62/872,374, filed on Jul. 10, 2019.
Prior Publication US 2022/0274112 A1, Sep. 1, 2022
Int. Cl. B01L 3/00 (2006.01)
CPC B01L 3/502792 (2013.01) [B01L 2200/141 (2013.01); B01L 2300/0645 (2013.01); B01L 2300/161 (2013.01); B01L 2400/0427 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A process for supplying a payload of an oil-encapsulated (OE) droplet within a digital microfluidic (DμF) network to a spatial region (SR) that is desirably not brought into contact with oil, the process comprising:
a) providing a DμF network of:
i. at least 3 edge-connected unit cells, each unit cell having; a volume for containing a droplet of fluid of volume less than 0.1 mL; and an electrode for field-effect displacement of an OE droplet from a neighbouring unit cell; and
ii. a supply for the network adapted to discretize a substantially liquid content of a reservoir into OE droplets, by moving the OE droplets into one of the unit cells, by actuation of an electrode of the network;
where the SR lies entirely within the volume of a first of the unit cells, the SR surrounded by a boundary extending continuously around it;
b) delivering to the first unit cell sufficient oil-free fluid to cover and seal off the boundary, covering the SR, the fluid being miscible with the payload; and,
while the oil-free fluid seals the boundary,
c) delivering at least one OE droplet from the supply to the first unit cell via the network, and allowing the OE droplet to merge with the oil-free fluid to produce a merged droplet that is surrounded by oil up to, and not including the boundary;
whereby the SR is in contact with no part of the oil shell during the process.