Drops Can Perpetually Bounce over a Vibrating Wettable Solid

Area of Science:

• Physics
• Fluid Dynamics
• Surface Science

Background:

• Bouncing drops on liquid baths exhibit chaotic dynamics and quantum analog behavior due to an air film.
• Perpetual bouncing on rigid solids remains challenging due to limitations in controlling drop motion.

Purpose of the Study:

• To demonstrate and characterize perpetual bouncing of drops on a vibrating rigid solid.
• To investigate the transition between bouncing and bound states of drops on vibrating surfaces.
• To develop a predictive model for drop trajectories on vibrating solids.

Main Methods:

• Vibrating an atomically smooth mica surface to study drop behavior.
• Analyzing drop motion and transition dynamics using high-speed observation.
• Developing a coupled linear spring model to simulate drop trajectories.

Main Results:

• Drop hovering time on a vibrating mica surface increased from seconds to minutes.
• Identified a transition to a bound state where drop motion is locked to the vibrating solid.
• The second spherical harmonic mode excitation dictates the transition between bouncing and bound states.
• A parameter-free model accurately predicts bouncing drop trajectories.

Conclusions:

• Vibrating rigid solids can sustain drop hovering for extended periods, surpassing liquid bath limitations.
• The study introduces a novel bound state for bouncing drops on solids.
• Results offer potential for precise manipulation of small liquid quantities using vibrating surfaces.