Development of a 3D graphene electrode dielectrophoretic device

Area of Science:

• Microfluidics
• Materials Science
• Electrical Engineering

Background:

• Dielectrophoresis (DEP) is a powerful technique for manipulating microparticles using non-uniform electric fields.
• Existing DEP devices often face limitations in reusability, complexity, or 3D manipulation capabilities.
• Graphene paper offers unique electrical and mechanical properties suitable for microdevice fabrication.

Purpose of the Study:

• To design and fabricate a novel, multi-layer, 3D electrode microdevice using graphene paper.
• To investigate the dielectrophoretic behavior of microparticles within the fabricated device.
• To assess the potential of the device for future biosensing applications.

Main Methods:

• Fabrication of a laminated microdevice by alternately stacking graphene paper and double-sided tape layers.
• Drilling a micro-well through the laminated structure using a computer-controlled micro drilling machine.
• Characterization of dielectrophoretic responses of 6 μm polystyrene beads across a range of conductivities and frequencies.

Main Results:

• Successful fabrication of a versatile, reusable, multi-layer DEP chamber.
• Demonstration of three-dimensional negative dielectrophoretic responses for polystyrene beads.
• Observed AC electroosmosis and electrothermal flows at low and high frequencies, respectively.
• Cross-over frequency values consistent with literature.

Conclusions:

• The novel 3D graphene paper microdevice is effective for dielectrophoresis.
• The device exhibits versatility and potential for integration into biosensing platforms.
• The fabrication protocol is adaptable for creating complex microfluidic DEP systems.