Ideal circle microswimmers in crowded media

Area of Science:

• Physics of complex systems
• Statistical mechanics
• Soft matter physics

Background:

• Microswimmers operate in natural, crowded environments.
• Interactions with obstacles significantly affect microswimmer transport properties.

Purpose of the Study:

• To model and analyze the transport of a single ideal circle microswimmer in a 2D disordered array of obstacles.
• To understand how obstacle density and microswimmer orbit radius influence movement patterns.

Main Methods:

• Computer simulations of a single ideal circle swimmer model.
• Analysis of movement on circular orbits and along obstacle surfaces.
• Calculation of mean-square displacements and diffusivities.

Main Results:

• Observed transitions between localized and diffusive states based on obstacle density and orbit radius.
• Identified underlying static percolation transitions driving these state changes.
• Determined the non-equilibrium state diagram for the microswimmer system.

Conclusions:

• Microswimmer transport is highly sensitive to obstacle interactions, leading to distinct localized and diffusive regimes.
• Transitions are linked to percolation phenomena, suggesting critical behavior.
• Subdiffusive transport near transition lines indicates a dynamic critical phenomenon.