An electroosmotic pump (EOP), or EO pump, is used for generating flow or pressure by use of an electric field. One application of this is removing liquid flooding

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

from channels and gas

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical ...

layers and direct

hydration Hydration may refer to: * Hydrate, a substance that contains water * Hydration enthalpy, energy released through hydrating a substance * Hydration reaction, a chemical addition reaction where a hydroxyl group and proton are added to a compound * ...

of the

proton exchange membrane A proton-exchange membrane, or polymer-electrolyte membrane (PEM), is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier, e.g. to oxygen and hydrogen g ...

in the

membrane electrode assembly A membrane electrode assembly (MEA) is an assembled stack of proton-exchange membranes (PEM) or alkali anion exchange membrane (AAEM), catalyst and flat plate electrode used in fuel cells and electrolyzers. PEM-MEA The PEM is sandwiched between ...

(MEA) of the proton exchange membrane fuel cells.

Principle

Electroosmotic pumps are fabricated from

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

nanospheres or hydrophilic porous glass, the

pump A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy. Pumps can be classified into three major groups according to the method they ...

ing mechanism is generated by an external

electric field An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field ...

applied on an electric double layer (EDL), generates high pressures (e.g., more than 340 atm (34 MPa) at 12 kV applied potentials) and high flow rates (e.g., 40 ml/min at 100 V in a pumping structure less than 1 cm³ in volume). EO pumps are compact, have no moving parts, and scale favorably with fuel cell design. The EO pump might drop the

parasitic load Parasitic load is a term used with regard to electrical appliances, railway locomotives and internal combustion engines. With regard to electrical appliances, it represents the power consumed even when the appliance is shut off, that is standby p ...

of water management in fuel cells from 20% to 0.5% of the fuel cell power.

Types

Cascaded electroosmotic pumps

High pressures or high flow rates are obtained by positioning several regular electroosmotic pumps in series or parallel respectively.

Porous electroosmotic pump

Porous pumping is created by the use of

sintered glass Fritted glass is finely porous glass through which gas or liquid may pass. It is made by sintering together glass particles into a solid but porous body. This porous glass body can also be called a frit. Applications in laboratory glasswar ...

Planar shallow electroosmotic pump

Planar shallow electroosmotic pumps are made of parallel shallow microchannels.

Electroosmotic micropumps

Electroosmotic effects can also be induced without external fields in order to power micron-scale motion. Bimetallic gold/silver patches have been shown to generate local fluid pumping by this mechanism when hydrogen peroxide is added to the solution. A related motion can be induced by silver phosphate particles, which can be tailored to generate reversible firework behavior among other properties.

References

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External links

Electroosmotic pump and its applicationsPrinciples of electroosmotic pumps
Hydrogen technologies Pumps Microfluidics Fuel cells