Transport of alignment active particles in funnel structures.

Area of Science:

• Physics
• Soft Matter Physics
• Statistical Mechanics

Background:

• Active particles exhibit self-propulsion and alignment, leading to complex collective behaviors.
• Confined geometries, such as asymmetric funnels, can induce directed motion (rectification) in active matter.
• Understanding particle transport in complex environments is crucial for designing active devices.

Purpose of the Study:

• To investigate the transport dynamics of alignment active particles within an array of asymmetric funnels.
• To explore how different alignment interactions (nematic and polar) affect particle rectification.
• To identify optimal conditions for directed transport of active particles.

Main Methods:

• Numerical simulations of active particle transport in a funnel array.
• Analysis of particle trajectories and velocity distributions.
• Systematic variation of alignment types, self-propulsion speed, and rotational diffusion.

Main Results:

• Multiple pathways in asymmetric funnels enrich transport behavior due to alignment interactions.
• Purely nematic alignment suppresses rectification in this system.
• Polar alignment's effect on rectification is dependent on self-propulsion speed, suppressing it at high values.
• Optimal self-propulsion speed and rotational diffusion coefficients were found to maximize directed velocity.

Conclusions:

• Alignment interactions significantly modify active particle transport in confined, complex geometries.
• The interplay between particle alignment, confinement asymmetry, and self-propulsion dictates rectification efficiency.
• The study reveals the existence of optimal parameters for achieving maximal directed transport, offering insights for controlling active matter systems.