Swimming microbots that mimic bacterial motion may be useful for precision tasks

Big Hero 6 may be more reality than fiction as researchers from Birmingham University aim to develop swimming microbots that mimic bacterial motion and may be able to one day perform precision tasks.

Despite the mounting research into swimming micromachines that have the ability to self-assemble in order to perform a certain task and then disassemble once that task is completed, challenges around controlling the individual bots when in a large group still remain.

Looking at this problem in more detail, a mathematical biologist from Birmingham University, Dr Tom Montenegro-Johnson, investigated how certain bacteria, such as E.Coli, can change their shape to move through their environment.

“These bacteria swim by a run-tumble method,” said Montenegro-Johnson in an interview with The Engineeer. “This means they have a ballistic trajectory for a certain amount of time called a run, where they swim in a straight line, and then they unbundle all of their flagella, and this causes a random re-orientation, and then they swim in a straight line again.”

Initially, the design of the micromachines (proof-of-concept) will be a flexible filament with both ends coated in platinum. Once placed into hydrogen peroxide, the platinum will catalyse, producing water and oxygen making a flow at the surface of the filament. This is where the shape of the filament will come into play as a straight one should act as a pump, a u-shaped one should translate and an s-shaped one should rotate.

This initial design will then be optimised using new mathematical tools to model the coupled elastic, fluid and chemical dynamics of slender filaments, additionally, the team will conceive new designs with greater functionality involving multiple filaments and ribbon-like structures. During this design phase a lab prototype will also be developed, which will be used to test and refine the theory.

It is anticipated that at the end of this project, the prototype will be developed enough that commercialisation of the technology will be possible and development of a ‘biocompatible’ prototype for minimally-invasive medical applications will be able to start.

The Engineering and Physical Sciences Research Council (EPSRC) is funding this project in addition to another being performed at the University of Birmingham to mark the Year of Engineering.

“The funding from EPSRC will allow me to translate a theoretical solution into a working prototype that can be used as a blueprint for new, more complex biomedical applications,” explained Montenegro-Johnson.