Electrostatic actuators for microfluidics and methods for using same

An apparatus for inducing movement of an electrolytic droplet, comprising:

• a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet;
• a distribution plate positioned within the chamber having an aperture therein, the distribution plate dividing the housing into upper and lower chambers;
• a lower electrode positioned below the lower chamber and below the aperture in the distribution plate, the lower electrode being separated from the lower chamber by an overlying hydrophobic layer;
• an upper electrode located above the upper chamber and above the aperture of the distribution plate, the upper chamber electrode being separated from the upper chamber by an underlying hydrophobic layer;
• a plurality of adjacent, electrically isolated droplet manipulation electrodes positioned above the lower electrode and below the lower chamber hydrophobic layer, wherein sequential droplet manipulation electrodes have substantially contiguous, hydrophobic upper surfaces that define a droplet travel path, wherein one of the lower droplet manipulation electrodes is positioned below the aperture in the distribution plate;
• first, second and third voltage generators that are electrically connected to, respectively, the lower and upper electrodes and the distribution plate, the first, second and third second voltage generators being configured to apply electrical potentials thereto, thereby inducing movement of the electrolytic droplet between the hydrophobic layers of the upper and lower chambers;
• and
• a fourth voltage generator that is electrically connected to the plurality of droplet manipulation electrodes and is configured to apply electrical potentials sequentially to the droplet manipulation electrodes along the droplet travel path, thereby inducing movement of the electrolytic droplet along the droplet travel path.

A method of moving an electrolytic droplet, comprising:

• providing a housing having an internal volume and a distribution plate residing therein, the distribution plate having an aperture and dividing the internal volume into upper and lower chambers, the lower chamber including an electrolytic droplet and each of the upper and lower chambers containing a liquid immiscible with the electrolytic droplet, the housing including a lower electrode electrically insulated from the lower chamber and underlying a hydrophobic layer, and the housing further including an upper electrode electrically insulated from the upper chamber and overlying a hydrophobic lower layer;
• positioning the electrolytic droplet above the lower electrode and beneath the distribution plate aperture;
• and
• applying electrical potentials to the lower and upper electrodes and to the distribution plate to draw the electrolytic droplet through the distribution plate aperture and to the upper chamber hydrophobic surface.

An apparatus for inducing movement of an electrolytic droplet, comprising:

• a housing having an internal volume;
• a plurality of adjacent, electrically isolated transport electrodes positioned in the housing, wherein sequential transport electrodes have substantially contiguous, hydrophobic surfaces, the transport electrodes defining a droplet travel path;
• a first voltage generator electrically connected to the transport electrodes, the first voltage generator configured to apply electrical potentials sequentially to each transport electrode along the droplet travel path, thereby inducing movement of an electrolytic droplet along the travel path;
• a plurality of gate electrodes, each of the gate electrodes positioned in the housing adjacent a respective transport electrode and having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent transport electrode, the gate electrodes being electrically connected;
• a second voltage generator connected to the plurality of gate electrodes and configured to apply electrical potentials thereto;
• a plurality of destination electrodes, each of which is positioned in the housing adjacent a respective gate electrode, each destination electrode having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent gate electrode;
• and
• a third voltage generator connected to the destination electrodes and configured to apply electrical potentials thereto.

A method of inducing movement in an electrolytic drop, comprising:

• providing a device comprising:
• a housing having an internal volume filled with a liquid immiscible with an electrolytic droplet;
• a plurality of adjacent, electrically isolated transport electrodes positioned in the housing, wherein sequential transport electrodes have substantially contiguous, hydrophobic surfaces, the transport electrodes defining a droplet travel path;
• a plurality of gate electrodes, each of the gate electrodes positioned in the housing adjacent a respective transport electrode and having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent transport electrode, the gate electrodes being electrically connected;
• and
• a plurality of destination electrodes, each of which is positioned in the housing adjacent a respective gate electrode, each destination electrode having a hydrophobic surface that is substantially contiguous with the hydrophobic surface of the adjacent gate electrode;
• positioning an electrolytic droplet on a first transport electrode;
• applying an electrical potential to a second transport electrode adjacent the first transport electrode sufficient to induce the electrolytic droplet to move from the first transport chamber electrode to the second transport electrode;
• repeating the applying step to continue inducing movement of the electrolytic droplet between adjacent lower chamber electrodes along the droplet travel path to a predetermined transport adjacent a first gate electrode, wherein the first gate electrode is at a ground state;
• applying an electrical potential to the first gate electrode as the predetermined transport electrode is at a ground state to induce the electrolytic droplet to move from the predetermined transport electrode to the first gate electrode, wherein a first destination electrode adjacent the first gate electrode is in a ground state;
• and
• applying an electrical potential to the first destination electrode as the first gate electrode is in a ground state to induce the electrolytic droplet to move from the first gate electrode to the first destination electrode.