Electrowetting-based valving and pumping systems
The present teachings relate to microfluidic valves and pumping systems, which may be suitable for controlling and facilitating liquid flow. Electrodes are disposed proximately to volumes containing a liquid. The liquid flow can be facilitated by electrowetting forces. Processes for controlling the flow of liquids, as well as for pumping liquids, are also disclosed.
1. A valving system comprising:
a first channel fluidly coupled to a first reservoir;
a second channel fluidly coupled to said first channel, said second channel having a first volume;
a first fluid obstruction included in the first volume,
wherein the first fluidic obstruction is configured to move to a first position and a second position in the first volume,
wherein the first fluidic objection is configured to block the second channel to prevent fluid communication between the first and second channels when the first fluidic obstruction is in the second position in the first volume, and
wherein the first fluidic obstruction is a fluid selected from a liquid droplet and a gas bubble;
an electrode proximate to each of said volumes and channels; and
a power source electrically coupled to each electrode, the power source being configured to provide an electrical potential difference at the interface between the electrode and the first fluidic obstruction sufficient to provide a net force to move the first fluidic obstruction within the first volume.
2. The system of claim 1 , further comprising:
a second volume comprising said first volume and at least a portion of said first channel;
a third channel fluidly coupled to said second volume, wherein said third channel comprises at least one section; and
a third volume opening into said at least one section.
3. The system according to claim 2 , further comprising an air vent fluidly connected to said third volume.
4. The system according to claim 2 , further comprising at least one additional volume opening into at least one additional section of said third channel, and an electrode proximate to said at least one additional volume.
5. The system according to claim 4 , further comprising an air vent fluidly connected to said at least one additional volume.
6. The system according to claim 4 , wherein said at least one additional volume comprises a first chamber and a second chamber, and an electrode is proximate to each of said chambers.
7. The system according to claim 6 , wherein said first chamber contains a fluid substantially immiscible with a liquid to be pumped by said system.
8. The system according to claim 2 , wherein said third volume comprises a first chamber and a second chamber, and an electrode is proximate to each of said chambers.
9. The system according to claim 8 , wherein said first chamber contains a fluid substantially immiscible with a liquid to be pumped by said system.
10. The system according to claim 1 , wherein a photoconductive material is electrically coupled to at least one of said electrodes.
11. A method of moving fluid in a valving system, the method comprising:
providing a valving system comprising
a reservoir, a channel fluidly connected to said reservoir,
a fluidic obstruction configured to be included in the channel,
wherein the fluidic obstruction is configured to move to a first position and a second position,
wherein the fluidic objection is configured to block the channel to prevent fluid communication between the reservoir and the channel when the fluidic obstruction is in the second position, and
wherein the fluidic obstruction is a fluid selected from a liquid droplet and a gas bubble; and
activating a power source to provide an electrical potential difference at an interface between the electrode and a fluidic obstruction, where the power source is electrically coupled to said at least one electrode, the power source being configured to provide an electrical potential, wherein the electrical potential difference is sufficient to provide a net force to move the fluidic obstruction.
12. The method according to claim 11 , wherein the valving system further comprises:
a plurality of channels fluidly connected to said reservoir;
at least one electrode associated with each channel, each of said electrodes being proximate to the intersection of the reservoir and one of said plurality of channels.
13. The method according to claim 11 , wherein a photoconductive material is electrically connected to the at least one electrode.