Droplet actuator devices and methods employing magnetic beads
AssigneesAdvanced Liquid Logic, Inc., Duke University
InventorsRamakrishna Sista, Vamsee K. Pamula, Michael G. Pollack, Vijay Srinivasan, Allen E. Eckhardt, Richard B. Fair
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Abstract
A method comprising effecting a change in a shape of a droplet, wherein the droplet is disposed over a substrate in sensing proximity to a sensor and the droplet has a starting surface area exposed to the sensor; and producing an expanded surface area of the droplet in the sensing proximity exposed to the sensor, wherein the expanded surface area exposed to the sensor is greater than the starting surface area exposed to the sensor.
Claims20
A droplet actuator device comprising:
- (a) an array of electrodes associated with a substrate and configured for conducting one or more droplet operations;
- (b) a magnet arranged to exert a magnetic field on a droplet positioned on a first set of one or more of the electrodes;
- and
- (c) a magnetic shield arranged to shield a droplet positioned on a second set of one or more of the electrodes from the magnetic field.
A droplet actuator device comprising magnet sets and electrode sets, wherein:
- (a) each electrode set comprises one or more electrodes associated with a substrate;
- (b) two or more electrode sets are:
- (i) arranged to form an array of electrodes;
- and
- (ii) configured for conducting one or more droplet operations;
- (c) each magnet set comprises one or more magnets;
- and
- (d) each magnet set is arranged in a relationship with an electrode set such that magnetic field(s) exerted by the magnet set restricts mobility of magnetically responsive particles to a locus which is proximate to the electrode set.
A droplet actuator configured for conducting operations involving a starting droplet comprising one or more magnetically responsive beads, a starting quantity of the substance, and a starting volume;
- the droplet actuator comprising:
- (a) a substrate including an electrode configured to communicate an electrical field to the starting droplet;
- (b) a magnet configured to generate a magnetic field affecting the one or more magnetically responsive beads;
- and
- (c) a processor in electrical communication with at least one of the electrode and the magnet and configured to initiate operations comprising:
- (i) magnetically immobilizing the one or more magnetically responsive beads at a location which is at a distance from a target droplet splitting zone;
- (ii) conducting one or more droplet operations comprising droplet dividing operations selected to divide the combined droplet to yield a set of droplets comprising:
- (1) a droplet comprising substantially all of the one or more magnetically responsive beads and having a decreased quantity of the substance relative to the starting concentration;
- and
- (2) a droplet substantially lacking the magnetically responsive beads.
Dependencies are inferred from the claim text.