We present herein a micro reactor set-up that enables parallel syntheses to be performed under electroosmotic flow conditions.

We report the measurement of electroosmotic mobilities in nanofluidic channels with rectangular cross sections and compare our results with theory. Nanofluidic channels were milled directly into borosilicate glass between two closely spaced microchannels with a focused ion beam instrument, and the nanochannels had half-depths (h) of 27, 54, and 108 nm and the same half-width of 265 nm. We measu...

Abstract: Presence of externally applied electric field can cause the flow field in the micron and submicron channels; this generated flow field is called electroosmotic. In this type of flow field, the presence of the external electric field causes the extra generated heat in the domain that may affect the performance of the system (Joule heating effect). In the present study, an analytical ap...

This paper reports on a rapid new method for in-situ sol-gel deposition of silica layers in PDMS microchannels. A two-step process is used; first allowing TEOS to diffuse briefly into the channel, followed by acid catalysed hydrolysis and condensation. The silica coating results in an increased and stabilised electroosmotic flow. With this novel method there is no need for pretreatment of the m...

Microcantilevers are finding wide applications in detecting biochemical agents. However, their usage has been limited to highly concentrated samples to ensure sufficient deposition of agents onto cantilevers. A pre-concentration or enrichment step will expand their application range to more dilute, practical samples and real-time detection. This paper reports the integration of in-situ particle...

Recent studies indicate increased efficiency of microfluidic ac electro-osmotic pumps by utilizing broken symmetries with raised steps on the electrodes. An experimental study on the dependence of ac electroosmosis in microchannels on solution chemistry for the new fast aceo stepped pumps is reported. Micro PIV was used to determine peak velocities for M mM ! " concentrations of KCl, NaCl, CaCl...

Field amplified sample stacking (FASS) is used to increase sample concentrations in electrokinetic flows. The technique uses conductivity gradients to establish a non-uniform electric field that accumulates ions within a conductivity gradient, and can be readily integrated with capillary electrophoresis. Conductivity gradients also cause gradients in near-wall electroosmotic flow velocities. Th...

Microfluidic field-effect flow control (FEFC) modifies the zeta potential of electroosmotic flow using a transverse electric field applied through the microchannel wall. Previously demonstrated in silicon-based and glass microsystems, FEFC is presented here as an elegant method for flow control in polymer-based microfluidics with a simple and low-cost fabrication process. In addition to direct ...

Electroosmotic pumps have been prepared using macroporous polymer monoliths with their pore surface grafted with the ionizable monomers 2-acrylamido-2-methyl-1-propanesulfonic acid and [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride, respectively. The effects of critical parameters such as pore size of the monolith, percentage of ionizable moieties in the grafted layer, crosslinking densi...