Under oil open-channel microfluidics empowered by exclusive liquid repellency

Area of Science:

• Microfluidics
• Biotechnology
• Bioengineering

Background:

• Under oil open microfluidics previously had limited resolution (millimeters) compared to closed systems (micrometers).
• Existing techniques restricted the functionality of open microfluidic channels.

Purpose of the Study:

• To develop a novel method for fabricating high-resolution open microfluidic channels under oil.
• To enhance the capabilities of open microfluidics for cellular sample manipulation and mass transport control.
• To demonstrate the application of these advanced open microfluidic channels in studying pathogenic fungal biofilms.

Main Methods:

• Utilized exclusive liquid repellency and an under oil sweep technique to prepare open microchannels directly under oil.
• Achieved channel dimensions reduced by up to three orders of magnitude compared to prior methods.
• Implemented spatial trapping of cellular samples and controlled mass transport, including passive pumping and reversible valves.

Main Results:

• Demonstrated the ability to create significantly smaller open microchannels (micrometer scale) under oil.
• Successfully achieved precise spatial trapping of diverse cellular samples within these channels.
• Enabled advanced mass transport control, including higher flow rates and stable, reversible fluidic operations.
• Applied the technology to dynamically measure dispersion from a pathogenic fungal biofilm.

Conclusions:

• The new under oil fabrication technique dramatically improves the resolution of open microfluidic channels.
• These enhanced open microfluidic systems offer advanced capabilities for cellular analysis and mass transport control.
• The developed technology broadens the potential applications of open microfluidics, particularly in studying complex biological systems like biofilms.