We discuss the structure of water at hydrophobic interfaces from the standpoint of its impact on electrokinetic phenomena in microfluidic devices fabricated from hydrophobic polymers such as Teflon or Zeonor. Water structuring at hydrophobic interfaces has been described as a source of interfacial charge (see Part 1, this issue), and dewetting phenomena, whether via depletion layers or nanobubb...

Charged and uncharged soft interfaces are present in a variety of microfluidic and biological systems. The electrokinetic properties of these fixed-diffuse-charge systems are dependent on (1) the components of the working fluid, (2) the bounding surface of the diffuse charge layer, and (3) the chemical and mechanical properties of the film itself. Here, we describe recent and past literature to...

In this paper, an improved bounce-back boundary treatment for fluid systems in the lattice Boltzmann method [Yin, X.; Zhang J. J. Comput. Phys. 2012, 231, 4295–4303] is extended to handle the electrokinetic flows with complex boundary shapes and conditions. Several numerical simulations are performed to validate the electric boundary treatment. Simulations are presented to demonstrate the accur...

Reliable and simple techniques for rapid assembly and patterning of colloid architectures advance the discovery and implementation of such nanomaterials. This work demonstrates rapid electrokinetic two-dimensional assembly of colloidal structures guided by the geometry of thin film heaters within a parallel-plate device. This system is designed to enable either independently addressable or mass...

A mathematical model and computer code for simulat ing electrokinetic fluid and sample manipulations in microfabricated fluidic devices (microchips) are described. The model accounts for mass transport mechanisms such as electrophoretic migration, bulk fluid motion due to electroosmosis, and diffusion. The interactive computer program implementing the model is capable of handling different chan...

The separation and on-line concentrations of lysergic acid diethylamide (LSD), iso-lysergic acid diethylamide (iso-LSD) and lysergic acid N,N-methylpropylamide (LAMPA) in human urine were investigated by capillary electrophoresis-fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as an anionic surfactant. A number of parameters such as buffer pH, SDS concentration, Brij-30 concentrati...

• Charged polymeric membranes are characterized by transmembrane streaming potential. Polymeric membrane structure can be affected a pressure application. Sequential difference doesn´t affects surface charge. hydraulic permeability. The effect of on the electrokinetic properties different charged is analysed. Electrokinetic characterization involve application increasing or decreasing differenc...

The introduction of metallic elements into microfluidic devices that support electrokinetic transport creates several fundamental issues relative to the high conductivity of the metal, which can act as a current shunt, causing profound effects on the transport process. Here we examine the use of Au-coated nanocapillary array membranes (Au NCAMs) as electrically addressable fluid control element...