Continuous flow microfluidic cell inactivation with the use of insulating micropillars for multiple electroporation zones

Pudasaini, Sanam; Perera, A T K; Das, Dhiman; Ng, Sum Huan; Yang, Chun

doi:10.1002/elps.201900150

Cited by 20 publications

(27 citation statements)

References 49 publications

(71 reference statements)

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“…Moreover, its gradient can induce particle dielectrophoresis (DEP) for passive focusing in either a straight microchannel with a varying cross-section [33] or a curved microchannel [34]. The so-called insulator-based dielectrophoresis (iDEP) in the former case has been extensively demonstrated to trap [35,36], pattern [37], electroporate [38], and separate [39][40][41][42][43] particles in a continuous electrokinetic flow under either a DC or a DC-biased AC electric field. The effects of insulator structure, electric field, particle properties (e.g., size, charge, and type), and surface treatment have all been investigated [44][45][46].…”

Section: Introductionmentioning

confidence: 99%

Passive Dielectrophoretic Focusing of Particles and Cells in Ratchet Microchannels

Malekanfard

Beladi-Behbahani

et al. 2020

Micromachines

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Focusing particles into a tight stream is critical for many microfluidic particle-handling devices such as flow cytometers and particle sorters. This work presents a fundamental study of the passive focusing of polystyrene particles in ratchet microchannels via direct current dielectrophoresis (DC DEP). We demonstrate using both experiments and simulation that particles achieve better focusing in a symmetric ratchet microchannel than in an asymmetric one, regardless of the particle movement direction in the latter. The particle focusing ratio, which is defined as the microchannel width over the particle stream width, is found to increase with an increase in particle size or electric field in the symmetric ratchet microchannel. Moreover, it exhibits an almost linear correlation with the number of ratchets, which can be explained by a theoretical formula that is obtained from a scaling analysis. In addition, we have demonstrated a DC dielectrophoretic focusing of yeast cells in the symmetric ratchet microchannel with minimal impact on the cell viability.

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Section: Introductionmentioning

confidence: 99%

Passive Dielectrophoretic Focusing of Particles and Cells in Ratchet Microchannels

Malekanfard

Beladi-Behbahani

et al. 2020

Micromachines

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“…The applications of insulator-based microfluidic devices in trapping, focusing, concentrating, separating, and sorting have been well-established. In our previous work, we developed a new microfluidic electroporation device with insulating micropillars for inducing locally enhanced electric field to inactivate yeast cells by using a DC field, where pillar diameter to gap ratio (i.e., d/D ratio) was kept as 2 [20]. A scaled-up electroporation device using insulating microbeads to intensify local electric field was also demonstrated [21].…”

Section: Introductionmentioning

confidence: 99%

Bacterial inactivation via microfluidic electroporation device with insulating micropillars

Pudasaini

Perera

et al. 2021

Electrophoresis

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Electroporation is a promising method to inactivate cells and it has wide applications in medical science, biology and environmental health. Here, we investigate the bacteria inactivation performance of two different microfluidic electroporation devices with rhombus and circular micropillars used for generating locally enhanced electric field strength. Experiments are carried out to characterize the inactivation performance (i.e., the log removal efficiency) of two types of bacteria: Escherichia coli (E. coli, gram-negative) and Enterococcus faecalis (E. faecalis, gram-positive) in these two microfluidic devices. We find that under the same applied electric field, the device with rhombus micropillars performs better than the device with circular micropillars for both E. coli and E. faecalis. Numerical simulations show that due to the corner-induced singularity effect, the maximum electric field enhancement is higher in the device with rhombus micropillars than that in the device with circular micropillars. We also study the effects of DC and AC electric fields and flowrate. Our experiments demonstrate that the use of the DC field achieves higher log removal efficiencies than the use of AC field.

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“…Insulator‐based dielectrophoresis (iDEP) is an emerging technology that has been increasingly used to handle a variety of particles (e.g., cells, colloids, viruses, DNA, and protein molecules) in microfluidic devices for various applications [1–3]. It exploits the in‐channel insulators such as hurdles, posts, and ridges to generate electric field gradients for diverse particle manipulations such as focusing [4,5], trapping [6–8], concentration [9–11], patterning [12], electroporation [13,14], separation, and sorting [15–20]. Compared to the traditional electrode‐based DEP [21–23], iDEP microdevices are easier to fabricate, inerter to electrochemical reactions, and less prone to fouling [24,25].…”

Section: Introductionmentioning

confidence: 99%

Joule heating‐enabled electrothermal enrichment of nanoparticles in insulator‐based dielectrophoretic microdevices

et al. 2020

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Insulator‐based dielectrophoresis (iDEP) exploits the electric field gradients formed around insulating structures to manipulate particles for diverse microfluidic applications. Compared to the traditional electrode‐based dielectrophoresis, iDEP microdevices have the advantages of easy fabrication, free of water electrolysis, and robust structure, etc. However, the presence of in‐channel insulators may cause thermal effects because of the locally amplified Joule heating of the fluid. The resulting electrothermal flow circulations are exploited in this work to trap and concentrate nanoscale particles (of 100 nm diameter and less) in a ratchet‐based iDEP microdevice. Such Joule heating‐enabled electrothermal enrichment of nanoparticles are found to grow with the increase of alternating current or direct current electric field. It also becomes more effective for larger particles and in a microchannel with symmetric ratchets. Moreover, a depth‐averaged numerical model is developed to understand and simulate the various parametric effects, which is found to predict the experimental observations with a good agreement.

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Continuous flow microfluidic cell inactivation with the use of insulating micropillars for multiple electroporation zones

Cited by 20 publications

References 49 publications

Passive Dielectrophoretic Focusing of Particles and Cells in Ratchet Microchannels

Passive Dielectrophoretic Focusing of Particles and Cells in Ratchet Microchannels

Bacterial inactivation via microfluidic electroporation device with insulating micropillars

Joule heating‐enabled electrothermal enrichment of nanoparticles in insulator‐based dielectrophoretic microdevices

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