(317f) Predator-Prey Targeting In Porous Medium by Chemical Swarm Robots

The multi-body dynamics of a system of composite Brownian particles (here referred to as the chemical swarm robots) in a porous environment is investigated. In general, the structure of the particles allows to encapsulate specific chemical agents (e.g., valuable chemical cargo or chemical signals) into their internal compartments. The encapsulated chemicals can be delivered towards a given target location and released in response to external stimuli (e.g., local change in a given solute concentration or temperature). Two types of particles are considered (1) prey particles characterised by increased motility, pre-programmed to release chemical signals (chemo-attractant) in the proximity of a given target and (2) predator particles undergoing chemotaxis with respect to the chemical signal concentration gradients, responsible for the delivery of valuable chemical cargo. The ability of the particles to coordinate their movement is determined by a multitude of individual attributes of the particles, such as diffusivity, rates of the chemical signal release, gradient sensing strength, initial distance and signalling threshold. For a number of applications, such as distributed chemical processing and targeted drug delivery, the understanding of factors that govern the collective behaviour of the particles, especially their ability to localise a given target is of immense importance.

A predator-prey model based on the combination of Brownian dynamics method for discrete particle movement and diffusion problem for continuous mass transport coupled through the chemotaxis phenomena is analysed in terms of the ability of the particles to localise a given target. The results demonstrate that the selected performance criteria (i.e., the mean localisation time, the success rate and the mean target residence time) can be improved when appropriate signalling process is chosen. Furthermore, for an optimum target localisation strategy, the topological complexity of the porous environment needs to be reflected. The performed series of parametric studies represent a computer-aided design of real chemical swarm robots, fully based on chemical principles.