Microcapillary-assisted dielectrophoresis for single-particle positioning

Area of Science:

• Biophysics
• Microfluidics
• Cellular Engineering

Background:

• Hydrodynamic trapping in microcapillaries faces challenges with particle/cell manipulation.
• Existing methods often rely on suction, limiting precise control and probing capabilities.

Purpose of the Study:

• Introduce microcapillary-assisted dielectrophoresis (μC-DEP) for enhanced particle and cell positioning.
• Address limitations of hydrodynamic trapping for applications like dynamic assays.
• Enable precise probing of trapped cells.

Main Methods:

• Utilized microcapillaries to generate localized positive dielectrophoresis (DEP) traps by concentrating electric field lines.
• Investigated trap strength via numerical simulations across various excitation frequencies.
• Experimentally validated effectiveness using 10 μm polystyrene microspheres in different solution conductivities.

Main Results:

• Demonstrated the ability of μC-DEP to create stable and localized dielectrophoretic traps.
• Confirmed trap effectiveness across a range of solution conductivities.
• Showcased successful positioning of individual cells, verified by cell viability assays and single-cell impedance spectroscopy.

Conclusions:

• Microcapillary-assisted dielectrophoresis (μC-DEP) offers a novel and effective method for precise particle and cell manipulation.
• The technique overcomes challenges associated with hydrodynamic trapping, enabling advanced applications.
• μC-DEP provides exclusive access for probing trapped cells, enhancing its utility in biological studies.