Controlled Transport of Individual Microparticles Using Dielectrophoresis

Abstract

A dielectrophoretic device employing a planar array of microelectrodes is designed for controlled transport of individual microparticles. By exciting the electrodes in sequence, a moving dielectrophoretic force is created that can drag a particle across the electrodes in a straight line. The electrode shapes are designed to counter any lateral drift of the trapped particle during transport. This facilitates single particle transport by creating a narrow twodimensional corridor for the moving dielectrophoretic force to operate on. The design and analysis processes are discussed in detail. Numerical simulations are performed to calculate the electromagnetic field distribution and the generated dielectrophoretic force near the electrodes. The Langevin equation is used for analyzing the trajectory of a microparticle under the influence of the external forces. The simulations show how the designed electrode geometry produces the necessary lateral confinement required for successful particle transport. Finally, experimental results are presented showing controlled bidirectional linear transport of single polystyrene beads of radius 10 and 5 μm for a distances 840 and 1100 μm, respectively. The capabilities of the proposed platform make it suitable for micro total analysis systems (μTAS) and lab-on-a-chip (LOC) applications.

Integrated Microfluidics for Single‐Cell Separation and On‐Chip Analysis: Novel Applications and Recent Advances

“…Similarly, Zaman et al developed a planar array of sequentially excitable electrodes to induce a moving dielectrophoretic force that allows the bidirectional movement of single particles on a straight line, countering any lateral drift. [ 43 ] While the suggested electrode geometry was initially optimized for polystyrene beads, the transport of a small cluster of yeast cells (approximately ≈5 μm in radius) was demonstrated.…”

“…• Label-free, contact-free separation • Separation based on intrinsic dielectric polarizability [21] • Unique electrical characteristics of different cell types identifiable [21] • Easy integration as microelectrode integration into microfluidic systems well-established • Wireless operation possible via bipolar electrode architecture [42,132,252,253] • DEP force acting on a cell/particle significantly varied as a function of distance away from an electrode edge [21] • Adverse effects on samples due to Joule heating when high electric field strength is required [25] • Possible degradation of the electrode and the nearby biological samples due to the electrochemical activity at the electrode-buffer interface [25,26,153] • Dependence on the electrical properties of the medium, which may necessitate specific buffer conditions that are optimal for cells [26,28,42,201] • Besides trapping, controlled transport and motion of cells and particles based on DEP [42,43] • Use of cheaper materials and easier fabrication methods [238,239,250] • Combination with other separation methods [251] Magnetophoresis • Well-established magnetic cell labeling [21] • Magnetic particle kits commercially available • Magnetic particle properties do not degrade and are commonly not affected by chemistry [21] • No significant magnetic noise usually present to interfere with cell/particle manipulation [21] • Relatively little heat generation [53] • Magnetic fields can penetrate most microfluidic materials [53] • Most often label-based • Biocompatibility of some magnetic particles not thoroughly studied [201] • Biocompatibility of ferrofluids for label-free magnetophoresis a key challenge [46] • Generation of controlled magnetic forces not straightforward [21] • Sorting efficiency limited by the strength of the magnetic field and the magnetic properties of the medium and particles…”

Dielectrophoretic force characteristics toward Lactobacillus casei on an oblique-patterned electrode

“…Biochip is a miniaturized test device for biosample analysis [1][2][3]. Various scientific and engineering concepts are used as the working principles of a biochip system, such as dielectrophoresis, microfluidics, and magnetism [4][5][6]. Dielectrophoresis (DEP)-based biochips are very popularly used to identify and analyze biosamples.…”

Conduction Conditions for Self-Healing of Metal Interconnect Using Copper Microparticles Dispersed with Silicone Oil

“…Cell/metal/semiconductor microparticles with diameters of a few micrometers or less are trapped between the interconnect upon the application of AC voltage between the interconnect. This phenomenon is referred to as “electric field trapping,” which has been used to separate specific microparticles [ 1 , 2 ], produce micro- and nanostructures of microparticles [ 3 , 4 , 5 , 6 , 7 ], and measure the properties of quantum dots [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. A self-healing metal interconnect that uses electric field trapping to repair cracks in metal interconnects has been proposed [ 15 , 16 , 17 ].…”