Liquid crystal-based open surface microfluidics manipulate liquid mobility and chemical composition on demand.

Area of Science:

• Materials Science
• Chemical Engineering
• Physics

Background:

• Controlling droplet mobility and chemical composition is crucial for advanced open surface microfluidics.
• Independent manipulation of droplet chemistry without altering movement presents a significant challenge.

Purpose of the Study:

• To design and demonstrate open surface microfluidic platforms using thermotropic liquid crystals (LCs).
• To achieve orthogonal control over droplet cargo release and mobility.

Main Methods:

• Utilized thermotropic liquid crystals (LCs) to create specialized surfaces for microfluidic applications.
• Employed experimental and theoretical approaches to analyze LC behavior and droplet interactions.
• Engineered LC surfaces loaded with sodium sulfide for heavy metal ion precipitation.

Main Results:

• Demonstrated that LC positional and orientational order decouple cargo release from droplet mobility through selective phase transitions.
• Achieved efficient precipitation of heavy metal ions in sliding droplets to sub-part-per-million concentrations.
• Maintained functionality for over 500 cycles without droplet pinning.

Conclusions:

• Liquid crystal (LC) surfaces offer a novel approach for designing open surface microfluidic systems.
• The developed LC platforms enable orthogonal control of droplet functionalities.
• This technology has potential applications in areas requiring precise chemical manipulation of micro-droplets.