Molecular modeling of odd viscoelastic fluids.

Area of Science:

• Soft Matter Physics
• Fluid Dynamics
• Active Matter

Background:

• Active particles in fluids exhibit complex behaviors not fully captured by traditional models.
• Understanding emergent macroscopic properties from microscopic interactions is crucial in soft matter.
• Odd effects in fluids, such as odd viscosity and elasticity, are an area of growing research interest.

Purpose of the Study:

• To introduce and analyze an active, stochastic microscopic model of particles with specific torque responses.
• To demonstrate that a coarse-grained description of this model leads to odd viscoelasticity.
• To provide a unified analytical framework for studying odd effects in active fluids.

Main Methods:

• Development of a microscopic model of active dumbbells with robotic beads exhibiting torque response.
• Analytical calculation of viscoelastic coefficients from the coarse-grained description of the model.
• Validation of theoretical results using molecular dynamics simulations.

Main Results:

• The coarse-grained description of the active dumbbell model yields odd viscoelasticity.
• Analytical expressions for the coefficients of the resulting viscoelastic model were derived.
• Simulations confirmed the analytical predictions, demonstrating the model's validity.

Conclusions:

• The proposed microscopic model successfully captures odd viscoelasticity in active fluids.
• The study establishes a theoretical framework applicable to various experimental and numerical investigations of odd fluid phenomena.
• This work bridges microscopic dynamics with macroscopic viscoelastic behavior in active matter systems.