Detecting particles flowing through interdigitated 3D microelectrodes

Area of Science:

• Microfluidics
• Biomedical Engineering
• Electrical Engineering

Background:

• Accurate cell counting in microchannels is crucial for in vitro assays like cell adhesion studies.
• Existing methods face challenges in large microchannel environments.

Purpose of the Study:

• To develop and validate a novel system for detecting particles in microchannels using interdigitated 3D electrodes and micropillars.
• To improve the accuracy and efficiency of cell counting in microfluidic devices.

Main Methods:

• Fabrication of interdigitated 3D electrodes around passivated, pillar-shaped silicon microstructures.
• Utilizing micropillar arrays spanning the channel height to detect particle passage via electrical resistance changes.
• Employing impedance measurements for system characterization and real-time particle detection.

Main Results:

• Demonstrated real-time particle detection by monitoring electrical resistance variations.
• Evaluated three distinct micropillar geometrical configurations.
• Numerical simulations characterized the sensitive volume and supported experimental findings, analyzing signal-to-noise ratio versus micropillar dimensions and count.

Conclusions:

• The developed 3D electrode and micropillar system offers a viable solution for real-time particle detection in microchannels.
• This technology enhances the capability of in vitro cell adhesion assays and other microfluidic applications requiring precise cell counting.