Electroosmotic pump

An electroosmotic pump (EOP), or EO pump, is used for generating flow or pressure by use of an electric field.[1][2] 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.[3]

Principle

Electroosmotic pumps are fabricated from silica nanospheres[4][5] 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.[6]

Types

Cascaded electroosmotic pumps

High pressures or high flow rates are obtained by positioning several regular electroosmotic pumps in series or parallel respectively.[7]

Porous electroosmotic pump

Porous pumping is created by the use of sintered glass.[8][9]

Planar shallow electroosmotic pump

Planar shallow electroosmotic pumps are made of parallel shallow microchannels.[10]

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.[11] A related motion can be induced by silver phosphate particles, which can be tailored to generate reversible firework behavior among other properties.[12]

See also

References
  1. Kirby, B.J. (2010). Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices. Cambridge University Press. ISBN 978-0-521-11903-0.
  2. Bruus, H. (2007). Theoretical Microfluidics.
  3. "microfluidics EO pump". Archived from the original on 2008-02-09. Retrieved 2008-01-18.
  4. Silica nanospheres
  5. Galvanostatic Measurements Archived June 28, 2008, at the Wayback Machine
  6. "Parasitic load in fuel cells". Archived from the original on 2007-12-28. Retrieved 2008-01-23.
  7. "Cascade EO pump" (PDF). Archived from the original (PDF) on 2007-06-29. Retrieved 2008-01-23.
  8. Porous glass electroosmotic pumps
  9. Sintred alumina electroosmotic pump
  10. "Planar shallow electroosmotic pump" (PDF). Archived from the original (PDF) on 2007-06-22. Retrieved 2008-01-23.
  11. 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.
  12. 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. PMID 28493638.
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