Self-phoretic oscillatory motion in a one-dimensional channel

Area of Science:

• Physics
• Chemical Engineering
• Soft Matter Physics

Background:

• Active particles, such as symmetric camphor grains, exhibit self-propulsion.
• Self-phoresis drives particle motion via self-generated chemical fields.
• Confined environments influence active particle behavior and dynamics.

Purpose of the Study:

• To investigate a simple model of active particles driven by repulsive self-phoresis.
• To analyze particle dynamics within a confined channel with chemical field reflection.
• To characterize the transition from passive to active oscillatory states.

Main Methods:

• Analytical construction of the phase diagram for the active particle system.
• Derivation of oscillation frequency and amplitude near the transition point.
• Perturbative analysis to describe particle dynamics and reflection mechanisms.

Main Results:

• A transition from a passive state (particle at midpoint) to an active state with regular oscillations was observed.
• Analytical methods accurately predict oscillation frequency and amplitude.
• A mechanism explaining particle reflection at channel edges in high activity regimes was developed.

Conclusions:

• The model successfully captures the transition to oscillatory behavior in confined active particles.
• Perturbative analysis provides accurate descriptions of particle dynamics across various oscillation amplitudes.
• Understanding particle reflection mechanisms is key to controlling active matter in confinement.