Vapor-mediated wetting and imbibition control on micropatterned surfaces

Area of Science:

• Surface science and nanotechnology.
• Fluid dynamics and interfacial phenomena.

Background:

• Wetting of micropatterned surfaces is crucial for technologies like spray cooling and inkjet printing.
• Controlling wetting often requires specialized materials, limiting broader applications.

Purpose of the Study:

• To demonstrate control over droplet spreading and wicking on hydrophilic patterns using vapor condensation.
• To investigate the underlying nonequilibrium mechanisms and their tunability.

Main Methods:

• Utilizing vapor from a lower-surface-tension liquid to induce condensation on micropatterned surfaces.
• Quantifying the interplay between pattern characteristics and vapor condensation effects.
• Analyzing the resulting wetting states and dynamic behaviors.

Main Results:

• Condensation-induced Marangoni forces delay capillary wicking, forming droplets on imbibed films.
• Macroscopic droplets can be maintained in an apparent partial wetting state, masking the pattern.
• Wetting states are tunable by adjusting vapor concentration, enabling reversible control.

Conclusions:

• Non-equilibrium processes, driven by vapor condensation, offer a versatile method to control wetting on micropatterned surfaces.
• This approach provides strategies for advanced surface manipulation, including guided droplet movement and liquid extraction for coating, cleaning, and drying applications.