Droplet interfaces in electro-wetting devices

Inventors

Holden, Matthew • White, James • Heron, Andrew John • Clarke, James Anthony • Hyde, Jason Robert • Hadwen, Benjamin James • Anderson, Sally

Assignees

Oxford Nanopore Technologies PLC

Abstract

Droplet interfaces are formed between droplets in an electro-wetting device comprising an array of actuation electrodes. Actuation signals are applied to selected actuation electrodes to place the droplets into an energised state in which the shape of the droplets is modified compared to a shape of the droplets in a lower energy state and to bring the two droplets into proximity. The actuation signals are then changed to lower the energy of the droplets into the lower energy state so that the droplets relax into the gap and the two droplets contact each other thereby forming a droplet interface. The use of sensing electrodes in the device permit electrical current measurements across the droplet interface. The sensing electrodes can be used for either (i) applying a reference signal during droplet actuation or (ii) recording electrical current measurements.

Core Innovation

An apparatus for performing experiments on droplet interfaces uses an electro-wetting device arranged to receive a fluid medium and droplets comprising liquid disposed on a hydrophobic surface of an electrically insulating layer. The electro-wetting device includes an array of actuation electrodes covered by the electrically insulating layer, and a control system applies actuation signals to selected actuation electrodes to manipulate received droplets and form at least one system of droplets having one or more droplet interfaces between the droplets.

A sensor system is configured to take electrical measurements between droplets in at least one formed system of droplets across droplet interfaces. The sensor system comprises a substrate supporting at least two sensor electrodes facing the hydrophobic surface, and the substrate comprises a hydrophobic material coating having apertures exposing only a part of the sensor electrodes. This arrangement enables electrical measurements across droplet interfaces formed on the hydrophobic insulating surface.

The apparatus supports experimentally manipulating formed droplet systems and measuring electrical signals across droplet interfaces, including electrical measurements of ion flow between droplets via a transmembrane pore. Electrical measurements can be performed over a selectable frequency range while applying a potential difference between sensor electrodes, and the measurements can be processed to analyse an analyte that interacts with a transmembrane pore in a droplet interface formed with a membrane of amphipathic molecules.

Claims Coverage

The independent claim recites three core inventive areas: an electro-wetting actuation electrode array on a hydrophobic insulating surface to form droplet-interface systems, a sensor system arranged to take electrical measurements between droplets across those interfaces, and a sensor-electrode substrate using a hydrophobic coating with apertures exposing only part of the sensor electrodes. Dependent claims refine measurement modality, measurement conditions, and analysis of an analyte interacting with a transmembrane pore and a membrane of amphipathic molecules.

Across the independent claim and its refinements, the inventive concept is anchored in forming droplet-interface systems by actuation of droplets on a hydrophobic insulating surface and enabling electrical measurements across those interfaces using sensor electrodes facing the hydrophobic surface through an apertured hydrophobic coating. Refinements narrow measurements to ion flow via a transmembrane pore and include processing of measurements to analyse an analyte interacting with a transmembrane pore and a membrane of amphipathic molecules.

Stated Advantages

Documented Applications

No documented applications found