Brownian microhydrodynamics of active filaments

Area of Science:

• Fluid dynamics
• Biophysics
• Materials science

Background:

• Slender bodies with spontaneous motion are prevalent in nature and technology.
• Modeling active filaments in fluid involves complex fluid-structure interactions, Brownian motion, and elasticity.

Purpose of the Study:

• To develop a theoretical model for active elastic filaments in a viscous fluid.
• To investigate the dynamics of minimally active filaments and their collective behavior.

Main Methods:

• Approximating the slender body as an elastic filament imposing non-equilibrium conditions at the fluid interface.
• Deriving equations of motion using momentum conservation and assuming slow viscous flow.
• Solving fluid-structure interactions via an integral equation, simplified using the Kirkwood-Riseman superposition approximation.

Main Results:

• Developed a model for active filament dynamics incorporating fluid-structure interactions and Brownian motion.
• Derived simplified equations of motion for efficient numerical analysis.
• Studied dynamical steady states in free and hinged minimally active filaments.

Conclusions:

• The model provides a foundation for studying collective phenomena in active filament suspensions.
• Highlights the importance of fluid-structure interactions and Brownian motion in active matter systems.
• Offers a framework for future research into self-propelled and interacting filaments.