Fluid pumping system based on electrochemically-induced surface tension changes

A low powered metered mixing device for mixing controlled volume of analyte and carrier fluids to a test chamber, the analyte and carrier fluids being carried in a conduit in fluid contact with sources of both fluids comprising in combination:

• first and second liquid metal pumps the first for pumping analyte, each including a pool of liquid metal confined within a containment vessel, an inner tubular member in fluid contact with the conduit, and with an open end disposed in the pool to divide the free upper surface of the pool into an actuation surface and a working surface, an electrolyte adapted for contact with the actuation surface, an electrode adapted for contact with electrolyte, and an electrode adapted for contact with the pool;
• check valves between the respective fluid source and the associated pump, and between each pump and the test chamber for directing pumped flow from the respective fluid sources to the test chamber;
• whereby voltage waveforms applied to the pump electrodes mix measured volumes of analyte and carrier in the test chamber for analysis.

A valve for regulating the flow of pressurized fluid through an attached conduit, the valve being actuated by a voltage from a power supply, the valve comprising:

• a liquid metal pool, a containment vessel for confining the pool, an inner tubular member with an open end disposed in the pool to divide a free upper surface of the pool into an actuation surface and a working surface, an electrolyte adapted for contact with the actuation surface, an electrode adapted for contact with the electrolyte, and an electrode adapted for contact with the pool, such that application of a voltage to the electrodes causes a surface tension change in the actuation surface and a resulting height change in the working surface, the inner tubular member including a membrane selectively moveable between a pinch off position and an open position with respect to the conduit according to the position of the working surface.

A liquid metal actuator, the actuator being actuated by a voltage from a power supply, the actuator comprising:

• a liquid metal pool, a containment vessel for confining the pool, an inner tubular member with an open end disposed in the pool to divide a free upper surface of the pool into an actuation surface and a working surface, an electrolyte adapted for contact with the actuation surface, an electrode adapted for contact with the electrolyte, and an electrode in contact with the pool, such that application of a voltage to the electrodes causes a surface tension change in the actuation surface and a resulting height change in the working surface, whereby a pressure differential is created above the working surface in the inner tubular member.

A method for pumping a fluid in a conduit comprising the steps of:

• providing a contained pool of a liquid metal;
• dividing the free upper surface of the pool into a working surface in hydraulic contact with the fluid, and a separate actuation surface in contact with an electrolyte;
• moving the working surface to exert a pumping action on the fluid by applying a voltage between the electrolyte and the pool to induce a surface tension and radius of curvature change in the actuation surface which is translated by the contained fluid into movement of the working surface.

A method for regulating flow of a pressurized fluid in a conduit, comprising the steps of:

• providing a contained pool of liquid metal;
• dividing the free upper surface of the pool into a working surface, in hydraulic contact with the fluid through a flexible membrane, and an actuation surface in contact with an electrolyte;
• moving the working surface to exert a force on the membrane to cause it to selectively pinch off and open the conduit to restrict and allow flow of the pressurized fluid, the moving being achieved by applying a voltage between the electrolyte and the pool to induce a surface tension change and a radius of curvature change in the actuation surface which is translated by the contained fluid into movement of the working surface to induce a pressure change above the working surface and thereby exerting the force on the membrane.