A Circular AC Electroosmotic Micropump for Chromatographic Applications

The interaction between ac electric fields and the induced charge in the double layer formed on top of electrodes generates steady motion of aqueous solutions. This phenomenon is termed ac electro-osmosis. Unidirectional fluid motion is obtained when the electrolyte is placed on top of an array of microelectrodes subjected to a travelling-wave potential. In this work, we analyse the generated fluid motion assuming that the electrodes are perfectly polarisable and making use of the nonlinear Gouy-Chapman model for the diffuse double layer. We approximate the applied potential at the level of the electrodes by a single-mode travelling wave. We present numerical and analytical solutions obtained in the weakly nonlinear regime and the results are discussed and related with previous experimental observations.

Section: Resultsmentioning

confidence: 93%

Pumping of electrolytes using travelling-wave electro-osmosis: a weakly nonlinear analysis

González

Ramos

Castellanos

2008

“…The most common geometry is to use asymmetric electrodes to induce an electric field and draw the diffuse layer charges along the surface of the electrodes (see Figure 11). The advantage of ACEO pumps is that relatively high velocities can be achieved for very small voltages of less than 10 V (Debesset et al 2004, Mpholo et al 2003. Further, as voltages are increased within this range, flow reversal can be achieved making a pump of this type bidirectional.…”

Section: Ac Electroosmoticmentioning

confidence: 99%

Recent advances in microscale pumping technologies: a review and evaluation

Iverson

Garimella

2008

427

249

Micropumping has emerged as a critical research area for many electronics and biological applications. A significant driving force underlying this research has been the integration of pumping mechanisms in micro Total Analysis Systems (μTAS) and other multi-functional analysis techniques. Uses in electronics packaging and micromixing and microdosing systems have also capitalized on novel pumping concepts. The present work builds upon a number of existing reviews of micropumping strategies by focusing on the large body of micropump advances reported in the very recent literature. Critical selection criteria are included for pumps and valves to aid in determining the pumping mechanism that is most appropriate for a given application. Important limitations or incompatibilities are also addressed. Quantitative comparisons are provided in graphical and tabular forms.

“…EO2 can be exploited to create micromixers (Takhistov et al 2003;Lastochkin et al 2004;Hu and Li 2007;Eckstein et al 2009), which is important for express analyses, as well for microsized pumps (Mishchuk et al 2009), intended, e.g., for the creation of compact analysis devices (Debesset et al 2004), intensification of electrodialysis (Dukhin and Mishchuk 1993;Mishchuk 1998a, b;Mishchuk et al 2001), etc. This study is concerned with the theoretical and experimental aspects of EO2 near ordered assemblies of ionexchange microspheres, and its application to directed fluid pumping in microchannels. The effect of bead size and arrangement, applied voltage and pulse frequency on the developed liquid flow is investigated.…”

Section: Introductionmentioning

confidence: 98%

Microfluidic pump based on the phenomenon of electroosmosis of the second kind

Mishchuk

Heldal²,

Volden³

et al. 2011

A micropump based on strong polarization of ion-exchange beads and corresponding actuation by electroosmosis of the second kind was designed and fabricated. Experimental results from operation with AC and DC voltage showed a close to second order relationship between flow and voltage, in good agreement with theory. The difference between experimental and theoretical flow rates and pressures is attributed to the hydrodynamic resistance of the channel network. A modified pump design which should yield higher flow rates and pressures was suggested.