Dielectrophoretic mobility determination in DC insulator‐based dielectrophoresis

Weiss, Noah; Jones, Paul V.; Mahanti, P.; Chen, Kang Ping; Taylor, Thomas J.; Hayes, Mark A.

doi:10.1002/elps.201100034

Cited by 32 publications

(48 citation statements)

References 52 publications

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“…Several other works in DC and AC DEP have focused on generating a constant gradient, but these focus on the longitudinal axis or within limited zones of interaction. 59–61 In contrast, this work is aimed at minimizing inhomogeneity across the lateral dimension.…”

Section: Introductionmentioning

confidence: 99%

Refinement of insulator-based dielectrophoresis

Crowther

Hayes

2017

Analyst

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The ability to separate analytes with increasingly similar properties drives the field of separation science. One way to achieve such separations is using trapping and streaming dielectrophoresis (DEP), which directly exploits the subtle differences in the electrophysical properties of analytes. The non-uniform fields necessary for DEP can be formed using various insulator shapes in microchannels. Current insulator shapes include triangles, diamonds, circles, and rectangles. However, all of these insulators pose problems for trapping, streaming, and sorting (deflection) as the induced fields/gradients are not behaviorally consistent across the lateral dimension. This leads to analytes experiencing different forces depending on their pathline in the microchannel and result in low resolution separations. Based on an iterative process that explored approximately 40 different insulator shapes, a design was chosen that indicated improved particle streamlines, better trapping efficiency, and consistent electrical environments across the lateral dimension. The design was assessed by simulations where the electric field, gradient of the electric field squared, and the ratio of the two were plotted. The improved design includes a unique new multi-length scale element. The multi-length scale structure streamlines the analyte(s) and improves homogeneity in the lateral dimension, while still achieving high gradients necessary for analyte separation using DEP. The design is calculated to keep analytes on the centerline which should improve resolution, and eliminate extraneous trapping zones. Behaviors consistent with the features of the simulations were observed in proof of principle experiments using representative test probes.

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Section: Introductionmentioning

confidence: 99%

Refinement of insulator-based dielectrophoresis

Crowther

Hayes

2017

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“…The dielectric force is proportional to the local electric field gradient squared and particle radius to the third power and is described in detail elsewhere [29, 30]. To examine this possibility quantitatively, the force was calculated within the construct of the 3D model using a dielectrophoretic mobility of −2 × 10 −8 cm 4 /(V 2 s) (recently published from this laboratory [26]) (Figure 5B). The addition of the dielectrophoretic effects provided an improved fit to the data and was likely a factor.…”

Section: Resultsmentioning

confidence: 99%

“…Ten microliters of stock sulfated fluorescent polystyrene particles of 1 μm diameter and 505/515 wavelength excitation/emission (Invitrogen, Carlsbad, CA, USA) were diluted to 2 mL with working buffer and sonicated for 15 minutes, yielding a concentration of approximately 2 × 10 8 particles/mL. Particles had an EP mobility of 3.5 × 10 −4 cm 2 /(Vs) as determined from previous experiments using similar conditions [26]. The inlet vial, glass plate reservoir, capillary bundle, and outlet vial were preconditioned with 0.1 M HCl for 10 minutes then flushed with the working buffer for 20 minutes by pressurizing the inlet with house nitrogen.…”

Section: Methodsmentioning

confidence: 99%

Quantitative assessment of flow and electric fields for electrophoretic focusing at a converging channel entrance with interfacial electrode

2012

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The electric field and flow field gradients near an electrified converging channel are amenable to separating and focusing specific classes of electrokinetic material, but the detailed local electric field and flow dynamics in this region have not been thoroughly investigated. Finite elemental analysis was used to develop a model of a buffer reservoir connected to a smaller channel to simulate the electrophoretic and flow velocities (which correspond directly to the respective electric and flow fields) at a converging entrance. A detailed PTV (Particle Tracking Velocimetry) study using charged fluorescent microspheres was performed to assess the model validity both in the absence and presence of an applied electric field. The predicted flow velocity gradient from the model agreed with the PTV data when no electric field was present. Once the additional forces that act on the large particles required for tracing (dielectrophoresis) were included, the model accurately described the velocity of the charged particles in electric fields.

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“…Chen et al [10] modeled particle pathlines in an iDEP sawtooth channel; particle pathlines in a curved microchannel have also been studied by Xuan's research group employing curvature-iDEP [11,12]. Particle dielectrophoretic mobilities were determined by Weiss et al [13] using a tapered section of a microchannel. Ros' research group [14][15][16] studied concentration profiles of nano-bioparticles (proteins and DNA) under streaming dielectrophoresis.…”

Section: Theorymentioning

confidence: 99%

Particle Manipulation in Insulator Based Dielectrophoretic Devices1

Gencoglu¹,

Olney²,

LaLonde³

et al. 2013

Journal of Nanotechnology in Engineering and Medicine

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Microfluidic devices can make a significant impact in many fields where obtaining a rapid response is critical, particularly in analyses involving biological particles, from deoxyribonucleic acid (DNA) and proteins, to cells. Microfluidics has revolutionized the manner in which many different assessments/processes are carried out, since it offers attractive advantages over traditional bench-scale techniques. Some of the advantages are: small sample and reagent amounts, higher resolution and sensitivity, improved level of integration and automation, lower cost and much shorter processing times. There is a growing interest on the development of techniques that can be used in microfluidics devices. Among these, electrokinetic techniques have shown great potential due to their flexibility. Dielectrophoresis (DEP) is an electrokinetic mechanism that refers to the interaction of a dielectric particle with a spatially non-uniform electric field; this leads to particle movement due to polarization effects. DEP offers great potential since it can be carried out employing DC and AC electric fields, and neutral and charged particles can be manipulated. This work is focused on the use of insulator based dielectrophoresis (iDEP), a novel dielectrophoretic mode that employs arrays of insulating structures to generate dielectrophoretic forces. Successful micro and nanoparticles manipulation can be achieved employing iDEP, due to its unique characteristics that allow for great flexibility. In this work, microchannels containing arrays of cylindrical insulating posts were employed to concentrate, sort and separate microparticles. Mathematical modeling with COMSOL V R was performed to identify optimal device configuration. Different sets of experiments were carried out employing DC and AC potentials. The results demonstrated that effective and fast particle manipulation is possible by fine tuning dielectrophoretic force and electroosmotic flow.

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Dielectrophoretic mobility determination in DC insulator‐based dielectrophoresis

Cited by 32 publications

References 52 publications

Refinement of insulator-based dielectrophoresis

Refinement of insulator-based dielectrophoresis

Quantitative assessment of flow and electric fields for electrophoretic focusing at a converging channel entrance with interfacial electrode

Particle Manipulation in Insulator Based Dielectrophoretic Devices1

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