Force-Electric Response Mechanism and Micro-Newton Quantification at Solid-Liquid Interfaces during Droplet Impact on...

Area of Science:

• Fluid dynamics
• Surface science
• Triboelectric nanogenerators

Background:

• Quantifying micro-Newton interfacial forces during droplet impact on inclined liquid-infused surfaces is challenging due to transient dynamics.
• Applications include droplet transport, self-cleaning, and energy generation.

Purpose of the Study:

• To develop a method for quantifying solid-liquid interfacial forces at the micro-Newton scale during droplet impact.
• To investigate the effects of Weber number and inclination angle on droplet-substrate interactions.

Main Methods:

• Integrated approach combining high-speed imaging and electrical measurements.
• Utilized triboelectric nanogenerator principles to create a force-electric response mechanism.
• In situ analysis of droplet morphology and electrical signals during impact on organogel surfaces.

Main Results:

• Established a positive correlation between maximum spreading area, peak impact current, and maximum adhesion resistance.
• Observed enhancements in spreading area, current, and resistance with increasing Weber number (28.65 to 241.02).
• Identified an optimal inclination angle of 45° for these parameters, with initial increase and subsequent decrease from 25° to 65°.

Conclusions:

• The developed force-electric mechanism enables micro-Newton scale quantification of interfacial forces.
• Findings provide fundamental insights into droplet impact dynamics and energy conversion.
• Results are valuable for optimizing surface designs in droplet manipulation and energy harvesting.