Aperiodic bursting dynamics of active rotors

Area of Science:

• Physics
• Chemical Engineering
• Nonlinear Dynamics

Background:

• Camphor rotors are self-propelled objects moving on an air-water interface.
• Their motion is driven by Marangoni forces arising from camphor diffusion.
• These rotors can exhibit complex dynamics, including periodic and aperiodic regimes.

Purpose of the Study:

• To investigate the dynamics of an active camphor rotor.
• To explore the entrainment of aperiodic bursting to periodic motion using external forcing.
• To study the behavior of coupled aperiodic camphor rotors and observe synchronization.

Main Methods:

• Experimental preparation of camphor rotors on paper strips.
• Observation of self-propelled motion at the air-water interface.
• Application of external periodic forcing to entrain rotor dynamics.
• Experiments with two coupled aperiodic camphor rotors.
• Development of a numerical point particle model with excitable equations.

Main Results:

• Camphor rotors transition from transient periodic dynamics to aperiodic bursting (irregular stop-and-go motion).
• External periodic forcing successfully entrains the aperiodic rotor into a regular regime.
• Coupled aperiodic rotors exhibit synchronized bursting, where one rotor follows the other.
• A numerical model accurately replicates the experimentally observed aperiodic bursting behavior.

Conclusions:

• Active camphor rotors display rich nonlinear dynamics, including aperiodic bursting.
• External forcing and inter-rotor coupling are effective in controlling and synchronizing these systems.
• The developed numerical model provides a valuable tool for understanding the underlying mechanisms of camphor rotor dynamics.