Microfluidic Gradient Formation by Maxwell-Wagner Polarization at an Aqueous Electric Interface

submitted by: zgagnon
This work integrates components from AC electrokinetics, microfluidics, and cell biology to produce tunable spatial chemical gradients in a microfluidic device for studying directed cell migration. I explore a new type of Maxwell Wagner polarization for the injection of aqueous liquid across a liquid-liquid interface. The rate of injection is tunable and used to manipulate fluid much the same way dielectrophoresis is used on bioparticles; fluid can be injected into different streamlines and...

Microfluidic Concentrator

submitted by: hsiaoping
This movie shows a microfluidic concentrator to concentrate proteins in a micro-chamber by using a conducting ion exchange granule comprising of nano-pores or nano-channels permeable to ions. We put fluorescein-tagged bovine serum albumin(BSA) in phosphate buffer in three different pH buffers. At the lowest pH (pH 5.5), we can only see the dark flow of non-fluorescent counter-ions to eject. At pH 6.6 and pH 11, in constrast, we can see a bright flow of fluorescent co-ions ejected from the...

Conducting PDMS for cell manipulation

submitted by: lewp0002
Cells are the basic element in humans, animals and plants. As they are so tiny, the manipulation of these small matters is impossible with humans’ hands and we cannot even see them with bare eyes. In this video, I am going to bring you into a microfluidic device; the place where cells and particles can be manipulated by conducting PDMS. This is a simple PDMS-based microfluidic device with two inlets and two outlets. But what make it interesting is conducting PDMS electrodes embedded...

Electrokinetic Concentration and Separation of Particles in Microfluidic Reservoirs

submitted by: xcxuan
This video exhibits the selective concentration and separation of 3 um particles from 1 um particles in the upstream reservoir of a straight microchannel. This size-based particle sorting arises from the negative dielectrophoresis induced at the reservoir-microchannel junction where the size mismatch of the reservoir and microchannel creates strong inherent electric field gradients. Such reservoir-based dielectrophoretic sorting is superior to existing insulator-based dielectrophoresis...

Electrothermal Flow in Insulator-Based Dielectrophoresis

submitted by: xcxuan
In this video 600 nm fluorescent particles were used visualize the electroosmotic fluid flow in insulator-based dielectrophoresis devices. The interaction of Joule heating-induced fluid inhomogeneities and electric field causes electrothermal fluid circulations upstream and downstream the microchannel constriction. By varying the DC and AC field components, we observed different flow patterns in the constriction region due to the competition of electroosmotic flow and electrothermal flow.

Biomicrofluidics Presents Small Matters: a Video Contest

submitted by: AIPJournals
Biomicrofluidics is pleased to announce a video contest, Small Matters. The contest is to highlight not only the exciting scientific merit of work conducted in the area of microfluidics and nanofluidics, but also the aesthetic and artistic qualities of the science. Winning entries will demonstrate a novel scientific concept in an elegant presentation. All finalists will be published in a special section of Biomicrofluidics ( http://bmf.aip.org/ ) and one grand prize winner will be chosen...