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 from channels and gas diffusion layers and direct hydration of the proton exchange membrane in the membrane electrode assembly (MEA) of the proton exchange membrane fuel cells.
Electroosmotic pumps are fabricated from silica nanospheres or hydrophilic porous glass, the pumping mechanism is generated by an external electric 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 of water management in fuel cells from 20% to 0.5% of the fuel cell power.
Cascaded electroosmotic pumps
Porous electroosmotic pump
Planar shallow electroosmotic pump
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.
- Capillary electrophoresis
- Electroosmotic flow
- Glossary of fuel cell terms
- Kirby, B.J. (2010). Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices. Cambridge University Press. ISBN 978-0-521-11903-0.
- Bruus, H. (2007). Theoretical Microfluidics.
- microfluidics EO pump
- Silica nanospheres
- Galvanostatic Measurements Archived June 28, 2008, at the Wayback Machine
- Parasitic load in fuel cells
- Cascade EO pump
- Porous glass electroosmotic pumps
- Sintred alumina electroosmotic pump
- Planar shallow electroosmotic pump
- Kline, Timothy R.; Paxton, Walter F.; Wang, Yang; Velegol, Darrell; Mallouk, Thomas E.; Sen, Ayusman (December 2005). "Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Formation". Journal of the American Chemical Society. 127 (49): 17150–17151. doi:10.1021/ja056069u. ISSN 0002-7863. PMID 16332039.
- Altemose, Alicia; Sánchez-Farrán, María Antonieta; Duan, Wentao; Schulz, Steve; Borhan, Ali; Crespi, Vincent H.; Sen, Ayusman (2017-05-30). "Chemically Controlled Spatiotemporal Oscillations of Colloidal Assemblies". Angewandte Chemie International Edition. 56 (27): 7817–7821. doi:10.1002/anie.201703239. ISSN 1433-7851.