Design of a Porous Electroosmotic Pump Used in Power Electronic Cooling

Microfluidic Systems with Ion-Selective Membranes

“…To ensure continuous flow into a downstream microchannel, a pressure maximum would then develop at the end of the nanoporous EO pump region, such that a backpressure reduces the high EO flow in the nanoporous pump and drives a pure pressure-driven flow in the microchannel. In the past 15 years, such nanoporous EO pumps have been developed by packing nanoparticles, fabricating polymer frits or nanoporous alumina in a chip, and sol-gel chemistry synthesis with an on-chip pressure as high as a few atmospheres for the most mechanically strong pumps (68)(69)(70)(71)(72). In Figure 4a, we show the scanning electron microscope (SEM) image of a nanoporous silica monolith that has been synthesized by sol-gel chemistry in a silica microcapillary and the large pressure (2 atm) it can sustain at the end of the monolith (Figure 4b).…”

A low-voltage nano-porous electroosmotic pump

“…One of the most promising micropumps for LOC applications is electroosmotic (EO) micropump, which drives the fluid motion using the surface charge of a channel wall that can spontaneously develop when the channel wall is in contact with an aqueous solution [16][17][18], or that can be artificially created through the control of gate potentials applied to the gate electrodes embedded beneath the channel wall [14,19]. The EO micropumps provide a high-pressure head and adjustable flow rate and also have the advantages of flexibility and biocompatibility for various LOC applications, which include microelectronics cooling [20,21], high performance liquid chromatography separations [22,23], drug delivery [24][25][26], water management in fuel cells [27,28], and micro-injection system [29][30][31][32]. However, most currently available EO micropumps require a very high driving voltage (on the order of 0.1-1 kV) to generate a sufficient flow rate, which in turn leads to electrolysis of water, oxidation of electrode surface, and Joule heating; eventually limiting the use of EO micropumps in portable LOC devices due to the requirement of a high-voltage power supply accessory.…”

Modelling electro-osmotic flow in porous media: a review

“…The maximum pressure work occurred at the middle point of the pump where P = P max /2 and Q = Q max /2: these values maximised the thermodynamic efficiency, representing the optimum operating condition. Berrouche et al (2009) modelled, designed and experimentally tested a porous EO pump (PEOP), fabricated on the base of two types of porous ceramics, sintered alumina and silica. The experimental results showed that the voltage applied to the disk is significantly lower than the one applied to PEOP (only 10.5 V were induced on the porous disk with an applied 150 V voltage at the electrode).…”