Nonlinear chemical reaction induced abnormal pattern formation of chemotactic particles.

The chemotactic behavior of particles is a widespread and important phenomenon that enables them to interact with the chemical species present in the environment. These chemical species can undergo chemical reactions and even form some non-equilibrium chemical structures. In addition to chemotaxis, particles can also produce or consume chemicals, which allows them to further couple with chemical reaction fields and thus influence the dynamics of the whole system. In this paper, we consider a model of chemotactic particle coupling with nonlinear chemical reaction fields. Intriguingly, we find the aggregation of particles occurs when they consume substances and move toward high-concentration areas, which is quite counterintuitive. In addition, dynamic patterns can also be found in our system. These results imply that the interaction between chemotactic particles and nonlinear reactions can result in much novel behavior and may further extend to explain the complex phenomena in certain systems.