Dynamically controlled dielectrophoresis using resonant tuning

Abstract

Electrically polarizable micro-and nanoparticles and droplets can be trapped using the gradient electric field of electrodes. But the spatial profile of the resultant dielectrophoretic force is fixed once the electrode structure is defined. To change the force profile, entire complex lab-on-a-chip systems must be re-fabricated with modified electrode structures. To overcome this problem, we propose an approach for the dynamic control of the spatial profile of the dielectrophoretic force by interfacing the trap electrodes with a resistor and an inductor to form a resonant resistor-inductor-capacitor (RLC) circuit. Using a dielectrophoretically trapped water droplet suspended in silicone oil, we show that the resonator amplitude, detuning, and linewidth can be continuously varied by changing the supply voltage, supply frequency, and the circuit resistance to obtain the desired trap depth, range, and stiffness. We show that by proper tuning of the resonator, the trap range can be extended without increasing the supply voltage, thus preventing sensitive samples from exposure to high electric fields at the stable trapping position. Such unprecedented dynamic control of dielectrophoretic forces opens avenues for the tunable active manipulation of sensitive biological and biochemical specimen in droplet microfluidic devices used for single-cell and biochemical reaction analysis.

Capturing Polar and Nonpolar Particles with an Electroadhesive Device Using Interfacial and Orientational Polarization

“…There is a large size distribution between three particles. This seems to be directly correlated to the dielectrophoretic force, which is the movement of polarizable particles under a nonuniform electric field. − However, the electroadhesion mechanism is more dominant than the dielectrophoretic force in this study, which illustrates the polarization mechanism, while the dielectrophoretic force is the movement of particles. In addition, the dielectric constant of the material is the main factor rather than the size of the particle in electroadhesion.…”

Mid-Infrared Optical Force Chromatography of Microspheres Containing Siloxane Bonds

“…Standard methods of molecular sorting include chromatography, electrophoresis, and flow cytometry, where the molecules are sorted based on their chemical and physical properties (i.e., polarity, , affinity, , and molecular structure). These methods are commonly combined with spectroscopic analysis to identify and quantify the sorted molecules, providing an integrated analysis system. ,− However, the aforementioned methods have several disadvantages, such as the requirement of a specific resin for a specific sample, , sample damage by the applied voltage, , and the necessity of molecular labeling. , Therefore, developing a versatile and efficient method of molecular sorting is essential to streamline the overall process of material research and production.…”