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Jun Yuan Chan, Aminuddin Bin Ahmad Kayani, Mohd Anuar Md Ali, Chee Kuang Kok, Burhanuddin Yeop Majlis, Susan Ling Ling Hoe, Marini Marzuki, Alan Soo-Beng Khoo, Kostya Ken Ostrikov, Md Ataur Rahman, Sharath Sriram
The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small sample volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell...
January 2018: Biomicrofluidics
Shuailong Zhang, Adele Nikitina, Yujie Chen, Yanfeng Zhang, Lin Liu, Andrew G Flood, Joan Juvert, M Dean Chamberlain, Nazir P Kherani, Steven L Neale, Aaron R Wheeler
Optoelectronic tweezers (OET) are a microsystem actuation technology capable of moving microparticles at mm s-1 velocities with nN forces. In this work, we analyze the behavior of particles manipulated by negative dielectrophoresis (DEP) forces in an OET trap. A user-friendly computer interface was developed to generate a circular rotating light pattern to control the movement of the particles, allowing their force profiles to be conveniently measured. Three-dimensional simulations were carried out to clarify the experimental results, and the DEP forces acting on the particles were simulated by integrating the Maxwell stress tensor...
March 5, 2018: Optics Express
Hitomi Mukaibo, Tonghui Wang, Victor H Perez-Gonzalez, Jirachai Getpreecharsawas, Jack T Wurzer, Blanca Lapizco-Encinas, James L McGrath
Insulator-based dielectrophoresis (iDEP) is a simple, scalable mechanism that can be used for directly manipulating particle trajectories in pore-based filtration and separation processes. However, iDEP manipulation of nanoparticles presents unique challenges as the dielectrophoretic force (<b><i>F</i></b><sub>DEP</sub>) exerted on the nanoparticles can easily be overshadowed by opposing kinetic forces. In this study, a molecularly thin, SiN-based nanoporous membrane (NPN) is explored as a breakthrough technology that enhances <b><i>F</i></b><sub>DEP</sub>...
March 12, 2018: Nanotechnology
Victor H Perez-Gonzalez, Roberto C Gallo-Villanueva, Braulio Cardenas-Benitez, Sergio O Martinez-Chapa, Blanca H Lapizco-Encinas
Insulator based dielectrophoresis (iDEP) is a microfluidic technique used for particle analysis in a wide array of applications. Significant efforts are dedicated to improve iDEP systems by reducing voltage requirements. This study assesses how the performance of an iDEP system, in terms of particle trapping, depends on the number of insulating obstacles longitudinally present in the microchannel. In analogy with Kirchhoff's loop rule, iDEP systems were analyzed as a series combination of electrical resistances, where the equivalent resistance of the post array is composed by a number of individual resistors (columns of insulating posts)...
March 12, 2018: Analytical Chemistry
Danielle V Polniak, Eric Goodrich, Nicole Hill, Blanca H Lapizco-Encinas
Dielectrophoresis (DEP), the migration of particles due to polarization effects under the influence of a nonuniform electric field, was employed for characterizing the behavior and achieving the separation of larger (diameter >5 μm) microparticles by exploiting differences in electrical charge. Usually, electrophoresis (EP) is the method of choice for separating particles based on differences in electrical charge; however, larger particles, which have low electrophoretic mobilities, cannot be easily separated with EP-based techniques...
February 24, 2018: Journal of Chromatography. A
Min Li, Robbyn K Anand
In this review, recent advances that leverage dielectrophoretic approaches to accomplish single-cell analysis (both "on-chip" and "off-chip") are discussed with special emphasis on eukaryotic cells. Dielectrophoresis as an electric-field-induced force utilized for cell manipulation can confer selectivity without labeling. Recent technical improvements have increased the volumetric throughput of the separation of cells from complex mixtures, introduced new strategies for massively parallel single-cell confinement for subsequent on-chip analysis, made possible selective transport of individual cells off-chip, and integrated preconcentration and prefocusing steps to enhance dielectrophoretic performance...
February 23, 2018: Analytical and Bioanalytical Chemistry
Alicia M Boymelgreen, Tov Balli, Touvia Miloh, Gilad Yossifon
Utilization of active colloids to transport both biological and inorganic cargo has been widely examined in the context of applications ranging from targeted drug delivery to sample analysis. In general, carriers are customized to load one specific target via a mechanism distinct from that driving the transport. Here we unify these tasks and extend loading capabilities to include on-demand selection of multiple nano/micro-sized targets without the need for pre-labelling or surface functionalization. An externally applied electric field is singularly used to drive the active cargo carrier and transform it into a mobile floating electrode that can attract (trap) or repel specific targets from its surface by dielectrophoresis, enabling dynamic control of target selection, loading and rate of transport via the electric field parameters...
February 22, 2018: Nature Communications
Jan Gimsa
AC fields induce charges at the structural interfaces of particles or biological cells. The interaction of these charges with the field generates frequency-dependent forces that are the basis for AC-electrokinetic effects such as dielectrophoresis (DEP), electrorotation (ROT), and electro-orientation. The effects can be used for the manipulation or dielectric single-particle spectroscopy. The observation of a particular effect depends on the spatial and temporal field distributions, as well as on the shape and the dielectric and viscoelastic properties of the object...
February 21, 2018: Electrophoresis
Yi Hu, Petia M Vlahovska, Michael J Miksis
A model to study the dynamics of colloidal particles in nonuniform electric fields is proposed. For an isolated sphere, the conditions and threshold for sustained (Quincke) rotation in a linear direct current (dc) field are determined. Particle dynamics becomes more complex with increasing electric field strength, changing from steady spinning around the particle center to time-dependent orbiting motion around the minimum field location. Pairs of particles exhibit intricate trajectories, which are a combination of translation, due to dielectrophoresis, and rotation, due to the Quincke effect...
January 2018: Physical Review. E
Coralie Siebman, Orlin D Velev, Vera I Slaveykova
The investigation of contaminant impact on algae requires rapid and reliable cell collection and optical detection. The capability of alternative current (AC) dielectrophoresis (DEP) collection of whole cell arrays with combined fluorescence microscopy detection to follow the alterations of chlorophyll fluorescence during environmental contaminant exposure was explored. The application of an AC-field of 100 V cm -1 , 100 Hz for 30 min to capture and immobilize the cells of green alga Chlamydomonas reinhardtii in two-dimensional (2D) arrays does not induce changes in chlorophyll fluorescence...
February 11, 2018: Biosensors
B Brazey, J Cottet, A Bolopion, H Van Lintel, P Renaud, M Gauthier
This paper presents the theoretical and experimental development of an integrated position sensor for lab-on-a-chip devices. The interest for single cell analysis is growing. However, this requires monitoring and controlling cell displacements in real time during their journey in the chip. Due to the high number of cells that must be monitored at the same time, classical vision-based sensors are not suitable. This paper aims to present an alternative based on impedance measurement. The position of the cells is obtained from the variation of impedance measured between two electrodes...
February 13, 2018: Lab on a Chip
Dongyang Cai, Qiaolian Yi, Chaohua Shen, Ying Lan, Gerald Urban, Wenbin Du
The full potential of microfluidic techniques as rapid and accurate methods for the detection of disease-causing agents and foodborne pathogens is critically limited by the complex sample preparation process, which commonly comprises the enrichment of bacterial cells to detectable levels. In this manuscript, we describe a microfluidic device which integrates H-filter desalination with positive dielectrophoresis (pDEP) for direct enrichment of bacterial cells from physiological samples of high conductivity and viscosity, such as cow's milk and whole human blood...
January 2018: Biomicrofluidics
Chenang Lyu, Jianping Wang, Matthew Powell-Palm, Boris Rubinsky
It was recently shown that electrolysis may play a substantial detrimental role in microfluidic electroporation. To overcome this problem, we have developed a non-electrolytic micro/nano electroporation (NEME) electrode surface, in which the metal electrodes are coated with a dielectric. A COMSOL based numerical scheme was used to simultaneously calculate the excitation frequency and dielectric material properties dependent electric field delivered across the dielectric, fluid flow, electroporation field and Clausius-Mossotti factor for yeast and E...
February 6, 2018: Scientific Reports
Sina Mahabadi, Fatima H Labeed, Michael P Hughes
Whilst personalized medicine (where interventions are precisely tailored to a patient's genotype and phenotype, as well as the nature and state of the disease) is regarded as an optimal form of treatment, the time and cost associated with it means it remains inaccessible to the greater public. A simpler alternative, stratified medicine, identifies groups of patients who are likely to respond to a given treatment. This allows appropriate treatments to be selected at the start of therapy, avoiding the common "trial and error" approach of replacing a therapy only once it is demonstrated to be ineffective in the patient...
February 5, 2018: Electrophoresis
Iain C Clark, Rohan Thakur, Adam R Abate
Microfluidic droplet sorting allows selection of subpopulations of cells, nucleic acids, and biomolecules with soluble assays. Dielectrophoresis is widely used for sorting because it generates strong forces on droplets, actuates rapidly, and is easy to integrate into microfluidic chips. However, existing device designs apply a short force, limiting the deflection of droplets, and therefore the speed and reliability of sorting. We describe a concentric design that applies a long force, allowing large deflections and increased reliability...
January 31, 2018: Lab on a Chip
Zhen Cao, Yu Zhu, Yang Liu, Shurong Dong, Xin Chen, Fan Bai, Shengxin Song, Junxue Fu
A nanoscale insulator-based dielectrophoresis (iDEP) technique is developed for rapid enrichment of proteins and highly sensitive immunoassays. Dense arrays of nanorods (NDs) by oblique angle deposition create a super high electric field gradient of 2.6 × 1024 V2 m-3 and the concomitant strong dielectrophoresis force successfully traps small proteins at a bias as low as 5 V. 1800-fold enrichment of bovine serum albumin protein at a remarkable rate of up to 180-fold s-1 is achieved using oxide coated Ag nanorod arrays with pre-patterned sawtooth electrodes...
January 26, 2018: Small
Kyle J M Bishop, Aaron M Drews, Charles A Cartier, Shashank Pandey, Yong Dou
Contact charge electrophoresis (CCEP) uses steady electric fields to drive the oscillatory motion of conductive particles and droplets between two or more electrodes. In contrast to traditional forms of electrophoresis and dielectrophoresis, CCEP allows for rapid and sustained particle motions driven by low-power DC voltages. These attributes make CCEP a promising mechanism for powering active components for mobile microfluidic technologies. This Review describes our current understanding of CCEP as well as recent strategies to harness it for applications in microfluidics and beyond...
January 19, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Hsiang-Hsi Ho, Chun-Lung Lin, Wei-Che Tsai, Liang-Zheng Hong, Cheng-Han Lyu, Hsun-Feng Hsu
We demonstrate the fabrication and characterization of silicon nanowire-based devices in metal-nanowire-metal configuration using direct current dielectrophoresis. The current-voltage characteristics of the devices were found rectifying, and their direction of rectification could be determined by voltage sweep direction due to the asymmetric Joule heating effect that occurred in the electrical measurement process. The photosensing properties of the rectifying devices were investigated. It reveals that when the rectifying device was in reverse-biased mode, the excellent photoresponse was achieved due to the strong built-in electric field at the junction interface...
January 16, 2018: Nanoscale Research Letters
Cunlu Zhao, Chun Yang
In this work, we report an effective microfluidic technique for continuous-flow trapping and localized enrichment of micro- and nano-particles by using induced-charge electrokinetic (ICEK) phenomena. The proposed technique utilizes a simple microfluidic device that consists of a straight microchannel and a conducting strip attached to the bottom wall of the microchannel. Upon application of the electric field along the microchannel, the conducting strip becomes polarized to introduce two types of ICEK phenomena, the ICEK flow vortex and particle dielectrophoresis, and they are identified by a theoretical model formulated in this study to be jointly responsible for the trapping of particles over the edge of the conducting strip...
January 16, 2018: Soft Matter
Giuseppe Nasti, Sara Coppola, Federico Olivieri, Veronica Vespini, Vito Pagliarulo, Pietro Ferraro
Electrophoresis (EP) and dielectrophoresis (DEP) are two well established methodologies to manipulate nanoparticles (NPs). Recently, a DEP by virtual electrodes platform was demonstrated on ferroelectric substrates where the driving force is due to the strong electric field generated by pyroelectric effect thus opening new scenarios for manipulating the matter. Such innovative approach named pyroelectric-DEP has several advantages over the traditional EP and DEP. However, a detailed study on this novel approach is required for understanding the complex pathways traced by nanoparticles (NP) under the action of the pyroelectric driven forces and thus for explaining the final patterns...
January 10, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
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