Electrokinetic Generation of High Pressures using Porous Microstructures

Abstract

The ability to generate high pressures using electrokinetic pumping of liquid through porous media is reported. Pressures in excess of 8000 psi have been achieved using silica capillaries packed with micron-size silica beads. A model is presented which captures absolute pressures, flowrates and power conversion efficiencies as well as the experimentally observed dependencies on pore size, applied electric field and electrical properties of the fluid. This previously unrecognized phenomena offers the possibility of creating a new class on micro- and meso-scale fluid devices where electroosmotic flow in a fine porous media is used as a pump to impart net useful hydraulic power to the fluid.