Hydrodynamical random walker with chemotactic memory

TL;DR

This paper models a micro-scale hydrodynamical random walker with chemotactic memory, analyzing how chemotactic signaling influences its diffusion behavior and directional movement in a fluid environment.

Contribution

It introduces a combined hydrodynamical and chemotactic model for micro walkers, revealing the impact of chemotactic memory on diffusion and directional bias.

Findings

Walker exhibits superdiffusive displacements along food gradient.

Chemotactic memory diminishes geometrical asymmetry effects.

Chemotactic index varies with memory time.

Abstract

A three-dimensional hydrodynamical model for a micro random walker is combined with the idea of chemotactic signaling network of E. coli. Diffusion exponents, orientational correlation functions and their dependence on the geometrical and dynamical parameters of the system are analyzed numerically. Because of the chemotactic memory, the walker shows superdiffusing displacements in all directions with the largest diffusion exponent for a direction along the food gradient. Mean square displacements and orientational correlation functions show that the chemotactic memory washes out all the signatures due to the geometrical asymmetry of the walker and statistical properties are asymmetric only with respect to the direction of food gradient. For different values of the memory time, the Chemotactic index (CI) is also calculated.