Dynamics of self-propelled filaments pushing a load

Area of Science:

• Physics
• Soft Matter Physics
• Biophysics

Background:

• Self-propelled filaments are model systems for active matter.
• Understanding their interaction with external objects is crucial for applications in micro-robotics and biological systems.

Purpose of the Study:

• To investigate the dynamics of worm-like filaments propelled by a tangential force when interacting with loads of varying size and shape.
• To identify distinct motion regimes and construct a phase diagram characterizing filament behavior.

Main Methods:

• Langevin dynamics simulations were employed to model filament-load interactions.
• Systematic exploration of parameters including load size/shape, propulsion strength, and thermal noise.

Main Results:

• Filament compression due to propulsion and friction leads to buckling instability and versatile motion.
• Four distinct regimes were identified: elongated, curved, beating, and alternating beating/circular motion.
• A phase diagram was constructed based on propulsion strength and load size.

Conclusions:

• Filament motion is highly sensitive to propulsion strength and load characteristics.
• Beating frequencies and rotational velocities exhibit power-law dependence on propulsive force, offering insights into active matter control.