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Can playing Spirograph lead to an ordered structure in self-propelled particles?
Mephin Philip Alamcheril1, Umang Jain1, Sujin B Babu1
1Out of Equilibrium Group, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. sujin@physics.iitd.ac.in.
Soft Matter
|October 7, 2021
Summary
This study models microorganism aggregation using self-propelled particles (SPPs). It reveals distinct static structures and dynamic orbital behaviors around attractive points (APs) based on coupling strength.
Area of Science:
- Microbiology
- Statistical Physics
- Computational Biology
Background:
- Microorganism aggregation impacts cellular infection dynamics.
- Understanding microbial movement is crucial for developing anti-aggregation strategies.
Purpose of the Study:
- To model microorganism aggregation and dynamics around attractive points (APs).
- To investigate the structural and dynamic behaviors of self-propelled particles (SPPs) in 2D and 3D.
Main Methods:
- Developed a simplified model of self-propelled particles (SPPs) with constant linear velocity.
- Simulated SPP behavior in 2D and 3D environments, including interactions with an attractive point (AP).
- Utilized Steinhardt bond order parameters to analyze static structures in the 3D model.
Main Results:
- Observed icosahedral structures for finite SPPs and hexagonal close-packed structures for infinite SPPs.
- Identified three distinct dynamic regions for a single SPP around an AP: rosette-like (weak coupling), circular (intermediate coupling), and static (strong coupling).
- Determined that radial distance depends on angular velocity in the rosette region and coupling constant in circular/static regions.
Conclusions:
- The SPP model effectively captures essential microorganism aggregation and AP interaction dynamics.
- Orbital trajectories around APs are predictable and categorized by coupling strength.
- Finite SPP systems exhibit similar behaviors to infinite systems when particle collisions are avoided.
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