Biological Microswimmers for Cargo Delivery Systems: Modelling, Simulations and Experiments

Bacteria, protozoa and microalgae have evolved mechanisms to self-propel.

The interactions between different types of Biological Microswimmers (BM) are relevant in natural processes such as the regulation of carbon and oxygen biogeochemical cycles and the toxin releasing by phytoplankton blooms under certain environmental conditions, but also in development of technological applications due to the emergence of a collective behaviour and a spatio-temporal synchronization.

BM have been used as transporters, showing promising results at carrying and releasing a cargo in a specified target.

However, there is still a lack of sharp control of the collective movement of BM towards a target, which implies a poor delivery of the cargo at the desired place.

This flaw comes from the fact that, in real scenarios, BM swim through complex porous media where interact with passive and active agents, and are subjected to external fields, such as light, concentration of chemicals and global background flow, that highly affect their motion and hinders its predictability.

Up to date, the concomitant effects of confinement, external fields and interactions with other BM or active agents, have not been taken into account in current simulations or experiments.

The proposed action, therefore, aims to develop a new computational approach that enables simulation of suspensions of interacting BM in complex confined environments, at the same time subjected to external fields, providing a platform to gain fundamental knowledge on the control of the collective behaviour of mixtures of BM under conditions compatible with the conceptual design of efficient cargo delivery systems.

The simulation platform will be feedbacked and tested with experiments, in which suspensions containing phototactic (C. reinhardtii) and chemotactic (E. coli) BM will be studied with microfluidics.