Electroosmotic pump

Principle

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.

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

Pumps based on porous media can be created using sintered glass or microporous polymer membranes with appropriate surface chemistry.

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. Titanium dioxide micromotors (TiO2) demonstrated swarming behavior in the absence or presence of additional fuels due to the self-generated electrolyte diffusioosmosis.

References

References

1. Kirby, B.J.. (2010). "Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices.". Cambridge University Press.
2. Bruus, H.. (2007). "Theoretical Microfluidics".
3. "microfluidics EO pump".
4. (2019-07-04). "Advancement of electroosmotic pump in microflow analysis: A review". Analytica Chimica Acta.
5. (January 2024). "Spatiotemporally Controllable Chemical Delivery Utilizing Electroosmotic Flow Generated in Combination of Anionic and Cationic Hydrogels". Advanced Functional Materials.
6. [https://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/9993/32105/01497386.pdf Silica nanospheres]
7. [http://microfluidics.stanford.edu/fuel_cells.htm Galvanostatic Measurements] {{webarchive. link. (June 28, 2008)
8. "Parasitic load in fuel cells".
9. "Cascade EO pump".
10. (December 2003). "Porous glass electroosmotic pumps: Design and experiments". Journal of Colloid and Interface Science.
11. [https://tel.archives-ouvertes.fr/docs/00/33/52/82/PDF/These_finale.pdf Sintred alumina electroosmotic pump]
12. (2017). "A large-area, all-plastic, flexible electroosmotic pump". Microfluidics and Nanofluidics.
13. "Planar shallow electroosmotic pump".
14. (December 2005). "Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Formation". Journal of the American Chemical Society.
15. (2017-05-30). "Chemically Controlled Spatiotemporal Oscillations of Colloidal Assemblies". Angewandte Chemie International Edition.
16. (2023-01-10). "Light-Powered, Fuel-Free Oscillation, Migration, and Reversible Manipulation of Multiple Cargo Types by Micromotor Swarms". ACS Nano.