Active Brownian Motion with Orientation-Dependent Motility: Theory and Experiments.

Area of Science:

• Physics
• Soft Matter Physics
• Statistical Mechanics

Background:

• Active Brownian motion describes self-propelled particles.
• Particle motility is typically assumed to be isotropic.
• Controlling active particle dynamics is crucial for applications.

Purpose of the Study:

• To investigate the dynamics of active particles with orientation-dependent motility.
• To develop a theoretical model for anisotropic active Brownian motion.
• To compare theoretical predictions with experimental results.

Main Methods:

• Experimental realization of active colloids with feedback-controlled velocity.
• Theoretical modeling using active Brownian motion framework.
• Analytical calculations of mean trajectories and mean-square displacements.

Main Results:

• Orientation-dependent motility induces significant anisotropy in particle displacement.
• Anisotropy persists in the long-time limit for displacement and mean-square displacement.
• Theoretical predictions show good agreement with experimental data.

Conclusions:

• A methodology for engineering anisotropic motilities in active Brownian particles is established.
• Orientation-dependent motility significantly impacts particle dynamics.
• Findings have implications for understanding microbial swimming and active matter systems.