Diffusive Memristor with CuS Nanoparticles Embedded in Polymeric Film as Artificial Nociceptor.

The threshold behavior and the ion diffusion dynamics in diffusive volatile memristors have a very uncanny resemblance to the transduction process of biological nociceptors. Hence, the diffusive memristors are considered the most suited for making artificial nociceptive systems. To facilitate their widespread adoption, it is imperative to develop polymeric or organic-inorganic hybrid material-based diffusive memristors that are economical, biocompatible, and easily processable.

A review of the zone broadening contributions in free-flow electrophoresis.

The broadening of analyte streams, as they migrate through a free-flow electrophoresis (FFE) channel, often limits the resolving power of FFE separations. Under laminar flow conditions, such zonal spreading occurs due to analyte diffusion perpendicular to the direction of streamflow and variations in the lateral distance electrokinetically migrated by the analyte molecules. Although some of the factors that give rise to these contributions are inherent to the FFE method, others originate from non-idealities in the system, such as Joule heating, pressure-driven crossflows, and a difference between the electrical conductivities of the sample stream and background electrolyte.

Application of an electrokinetic backflow for enhancing pressure-driven charge based separations in sub-micrometer deep channels.

In this article, we report significant improvements in the resolving power of pressure-driven charge based separations performed in sub-micrometer deep glass channels upon introducing an electrokinetic backflow in the system. Such improvements are realized as axial electrophoresis aids the pressure-driven separation process in negatively charged glass conduits under these conditions. In addition, the electroosmotic backflow slows down the bulk transport of the background electrolyte subjecting the sample to the separation field for prolonged periods and yields a higher fluid shear across the channel depth further assisting the separation process.

Electrokinetic stacking of particle zones in confined channels enabling their UV absorbance detection on microchips.

In this article, we report a simple approach to stacking micro- and nanoparticle zones by electrokinetically migrating them through moderately confined channels of uniform cross-section. Experiments show the reported pre-concentration process to initiate at the tail end of the zone following its electrokinetic injection, with the stacked region migrating faster than the rest of the sample band. This effect causes the particles traveling in front to merge into the stacked region making it grow both in size and concentration.

On-chip pressure generation using a gel membrane fabricated outside of the microfluidic network.

On-chip generation of pressure gradients via electrokinetic means can offer several advantages to microfluidic assay design and operation in a variety of applications. In this article, we describe a simple approach to realizing this capability by employing a polyacrylamide-based gel structure fabricated within a fluid reservoir located at the terminating end of a microchannel. Application of an electric field across this membrane has been shown to block a majority of the electroosmotic flow generated within the open duct yielding a high pressure at the channel-membrane junction.