Dispensing nano-pico droplets and liquid patterning by pyroelectrodynamic shooting

Area of Science:

• Microfluidics
• Biotechnology
• Materials Science

Background:

• Precise liquid manipulation at the micro- and nanoscale is crucial for biotechnology, combinatorial chemistry, and ink-based patterning.
• Existing liquid dispensing methods often rely on complex electrode setups and high-voltage electronics, limiting their accessibility and application scope.

Purpose of the Study:

• To introduce a simplified method for dispensing attolitre liquid droplets using pyroelectrohydrodynamics.
• To demonstrate a technique that avoids the need for electrodes, nozzles, or intricate circuitry.

Main Methods:

• Utilizing a pyroelectrohydrodynamic dispenser with a lithium niobate substrate.
• Activating local pyroelectric forces by scanning a heated tip or infrared laser over the substrate.
• Drawing liquid droplets from sessile drops or liquid film reservoirs and depositing them on the substrate's underside.

Main Results:

• Successfully demonstrated the drawing and deposition of attolitre liquid droplets.
• Showcased the ability to alter droplet trajectory by manipulating the heat source, enabling pattern formation.
• Confirmed that the system operates without requiring electrodes, nozzles, or external circuits.

Conclusions:

• The pyroelectrohydrodynamic dispenser offers a simple and effective approach for micro- and nanoscale liquid manipulation.
• This electrode-free method has significant potential for applications in biochemical assays, micro-transport, and mixing processes.