3D Insulator-based dielectrophoresis using DC-biased, AC electric fields for selective bacterial trapping

Area of Science:

• Biophysics
• Microfluidics
• Electrical Engineering

Background:

• Insulator-based dielectrophoresis (iDEP) utilizes electric fields for particle manipulation.
• DC-biased AC electric fields can improve iDEP performance.
• 3D microfluidic devices offer advanced capabilities in particle handling.

Purpose of the Study:

• To present the first 3D iDEP device combined with DC-biased AC fields.
• To demonstrate enhanced particle separation and selective cell trapping.
• To investigate the performance of 3D iDEP at low potentials.

Main Methods:

• Fabrication of 3D microfluidic chips using reactive ion etch lag and photolithography.
• Rapid prototyping of 3D iDEP devices from PDMS polymer in glass molds.
• Application of DC-biased AC electric fields for particle manipulation.

Main Results:

• Achieved high trapping efficiency in 3D iDEP devices at potentials as low as 200 Vpp.
• Successfully separated Escherichia coli from 1 μm beads.
• Demonstrated selective trapping of live Staphylococcus aureus cells from dead cells.

Conclusions:

• The novel 3D iDEP device with DC-biased AC fields provides efficient particle separation and selective bacterial trapping.
• This technology advances microfluidic applications for biological sample analysis.
• It offers a powerful tool for situations where conventional DC iDEP selectivity is insufficient.