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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Nanoparticle Sorting Technique using Laser Induced Dielectrophoresis with Phase Modulated Interference
摘要： A novel nanoparticle sorting technique using the laser-induced dielectrophoresis (LIDEP) and phase modulated interference has been developed. In this paper, a proposed method of nanoparticle sorting and fabrication of microfluidic device are reported, and the validity of a method is discussed.
关键词： microfluidic,optical phase modulation,separation,nanoparticle,laser-induced dielectrophoresis,sorting
更新于2025-09-12 10:27:22
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Sensitive Bacterial Detection via Dielectrophoretic Enhanced Mass Transport Using Surface Plasmon Resonance Biosensors
摘要： The performance of surface plasmon resonance (SPR)-based bacterial biosensors is often compromised due to diffusion-limited mass transport of bacteria to the sensing surface. In this work, dually functional interdigitated electrodes (IDEs) were developed to sustain SPR, and increase bacterial mass transport through external application of dielectrophoresis (DEP). IDEs were defined into 50 nm thick Au films with fixed electrode gaps (EG = 5 μm) and varied electrode widths (EW = 10, 20, and 100 μm), and referred to as interdigitated SPR (iSPR) chips. The iSPR chips with EW = 100 μm can effectively support SPR, with comparable sensitivity to the conventional SPR chips. The surfaces of iSPR chips (EW = 100 μm) were modified with mannose to target the FimH adhesin of E. coli and increase cellular adhesion. An LOD of ~3.0 x 102 CFU/mL E. coli was achieved on mannosylated iSPR chips under pDEP condition, which is about five orders of magnitude improvement compared to the mannosylated conventional SPR chips without DEP. Furthermore, secondary antibody amplification enabled selective enhancement of dilute (103 CFU/mL), E. coli suspensions, while no amplification was observed for concentrated (108 CFU/mL), non-target (S. epidermidis) bacterial suspensions. The results presented here indicate a great potential of the incorporation of DEP into SPR biosensors for rapid, sensitive, and specific detection of bacteria with broad applications in the areas of biomedical diagnostics, environmental monitoring, food safety, and homeland security.
关键词： bacterial detection,dielectrophoresis,surface plasmon resonance,mass transport,biosensors
更新于2025-09-10 09:29:36
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An Optically Induced Dielectrophoresis (ODEP)-Based Microfluidic System for the Isolation of High-Purity CD45neg/EpCAMneg Cells from the Blood Samples of Cancer Patients—Demonstration and Initial Exploration of the Clinical Significance of These Cells
摘要： Circulating tumour cells (CTCs) in blood circulation play an important role in cancer metastasis. CTCs are generally de?ned as the cells in circulating blood expressing the surface antigen EpCAM (epithelial cell adhesion molecule). Nevertheless, CTCs with a highly metastatic nature might undergo an epithelial-to-mesenchymal transition (EMT), after which their EpCAM expression is downregulated. In current CTC-related studies, however, these clinically important CTCs with high relevance to cancer metastasis could be missed due to the use of the conventional CTC isolation methodologies. To precisely explore the clinical signi?cance of these cells (i.e., CD45neg/EpCAMneg cells), the high-purity isolation of these cells from blood samples is required. To achieve this isolation, the integration of ?uorescence microscopic imaging and optically induced dielectrophoresis (ODEP)-based cell manipulation in a micro?uidic system was proposed. In this study, an ODEP micro?uidic system was developed. The optimal ODEP operating conditions and the performance of live CD45neg/EpCAMneg cell isolation were evaluated. The results demonstrated that the proposed system was capable of isolating live CD45neg/EpCAMneg cells with a purity as high as 100%, which is greater than the purity attainable using the existing techniques for similar tasks. As a demonstration case, the cancer-related gene expression of CD45neg/EpCAMneg cells isolated from the blood samples of healthy donors and cancer patients was successfully compared. The initial results indicate that the CD45neg/EpCAMneg nucleated cell population in the blood samples of cancer patients might contain cancer-related cells, particularly EMT-transformed CTCs, as suggested by the high detection rate of vimentin gene expression. Overall, this study presents an ODEP micro?uidic system capable of simply and effectively isolating a speci?c, rare cell species from a cell mixture.
关键词： optically induced dielectrophoresis (ODEP),cancer metastasis,cell isolation,micro?uidic systems,circulating tumour cells (CTCs)
更新于2025-09-10 09:29:36
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A novel method to design an electro-kinetic platform based on complementary metal-oxide semiconductor technology using SKILL scripting of cadence
摘要： The dielectrophoresis (DEP) is the motion of polarizable particles which is a result of the interaction between a non-uniform electric field and the induced dipole moment of these particles. The electro-kinetic DEP is a widely used technique for biological cells' manipulation, characterization and separation. The electro-kinetic DEP consists of three major configurations, they are; traveling wave dielectrophoresis (twDEP), electro-rotation dielectrophoresis (rotDEP), and levitation (levDEP). In this paper, a design of electrokinetic platform that includes the three electrokinetic configurations is presented and discussed. The design of the electrokinetic platform is implemented and simulated using 130 nm complementary metal-oxide-semiconductor (CMOS) technology. Also, this paper presents a developed technique to design the electrokinetic platform's electrodes. This developed technique is the usage of SKILL scripting of cadence (SSC) language. CMOS is a technology which is used to fabricate integrated circuits (IC). SKILL is a scripting language which supports the automation of a specific layout design by commands. The layout of electrokinetic DEP platform is developed using SSC. The performance of the developed electrokinetic platform using SSC versus the platforms based on the other traditional techniques is presented and evaluated using COMSOL Multiphysics?.
关键词： Electro-kinetic,Dielectrophoresis,Traveling,Levitation,SKILL scripting of cadence
更新于2025-09-09 09:28:46
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Sorting and manipulation of biological cells and the prospects for using optical forces
摘要： Contemporary biomedical research requires development of novel techniques for sorting and manipulation of cells within the framework of a microfluidic chip. The desired functions of a microfluidic chip are achieved by combining and integrating passive methods that utilize the channel geometry and structure, as well as active methods that include magnetic, electrical, acoustic and optical forces. Application of magnetic, electric and acoustics-based methods for sorting and manipulation have been and are under continuous scrutiny. Optics-based methods, in contrast, have not been explored to the same extent as other methods, since they attracted insufficient attention. This is due to the complicated, expensive and bulky setup required for carrying out such studies. However, advances in optical beam shaping and computer hardware, and software have opened up new opportunities for application of light to development of advanced sorting and manipulation techniques. This review outlines contemporary techniques for cell sorting and manipulation, and provides an in-depth view into the existing and prospective uses of light for cell sorting and manipulation.
关键词： Cell manipulation,Optical sorting,Microfluidics,Acoustic sorting,Cell separation,Dielectrophoresis,Magnetic manipulation
更新于2025-09-04 15:30:14
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Frequency-Modulated Wave Dielectrophoresis of Vesicles And Cells: Periodic U-Turns at the Crossover Frequency
摘要： We have formulated the dielectrophoretic force exerted on micro/nanoparticles upon the application of frequency-modulated (FM) electric fields. By adjusting the frequency range of an FM wave to cover the crossover frequency fX in the real part of the Clausius-Mossotti factor, our theory predicts the reversal of the dielectrophoretic force each time the instantaneous frequency periodically traverses fX. In fact, we observed periodic U-turns of vesicles, leukemia cells, and red blood cells that undergo FM wave dielectrophoresis (FM-DEP). It is also suggested by our theory that the video tracking of the U-turns due to FM-DEP is available for the agile and accurate measurement of fX. The FM-DEP method requires a short duration, less than 30 s, while applying the FM wave to observe several U-turns, and the agility in measuring fX is of much use for not only salty cell suspensions but also nanoparticles because the electric-field-induced solvent flow is suppressed as much as possible. The accuracy of fX has been verified using two types of experiment. First, we measured the attractive force exerted on a single vesicle experiencing alternating-current dielectrophoresis (AC-DEP) at various frequencies of sinusoidal electric fields. The frequency dependence of the dielectrophoretic force yields fX as a characteristic frequency at which the force vanishes. Comparing the AC-DEP result of fX with that obtained from the FM-DEP method, both results of fX were found to coincide with each other. Second, we investigated the conductivity dependencies of fX for three kinds of cell by changing the surrounding electrolytes. From the experimental results, we evaluated simultaneously both of the cytoplasmic conductivities and the membrane capacitances using an elaborate theory on the single-shell model of biological cells. While the cytoplasmic conductivities, similar for these cells, were slightly lower than the range of previous reports, the membrane capacitances obtained were in good agreement with those previously reported in the literature.
关键词： Cell,Frequency-modulated wave,Crossover frequency,The Clausius-Mossotti factor,Spectroscopy,Dielectrophoresis,Vesicle
更新于2025-09-04 15:30:14