Novel Surface Treatment of Micro-Channels for the Control of Electro-Osmosis in Nano-Scale Instruments

Electroosmosis is used for the movement of fluids through the small channels in analytical and other instrumentation which is designed to operate at the "nano-scale" on single microchips, in addition to its use in capillary electrophoresis (an established small volume, high efficiency separation technique). One limitation of using electroosmosis in these applications is the lack of control and the poor reproducibility of the electroosmotic flow in standard systems. In an effort to provide dynamic manipulation of electroosmosis, and thus fully control and stabilize this flow, a radial voltage field is applied across the wall of the capillary. This technique provides control, but only at low pH (