Towards Mass-Scale Micro-Assembly Systems Using Magnetotactic Bacteria

Magnetotactic bacteria (MTB) can be used in a coordinated fashion to assemble micro-objects in an orderly manner. To perform micro-assembly tasks, magnetotaxis-based control is used where a directional magnetic field is generated to induce a torque on an embedded chain of membrane-based magnetic nanoparticles (MNP) named magnetosomes. Such chain acts like a nano-compass or a nano-steering system embedded in each bacterium. Such magnetotaxis-based control is then used to orient the MTB in such a way that the laminar flow created by their flagella bundles provides a displacement force on the micro-objects being assembled. Since the force is generated by the bacteria, relatively large micro-objects can be moved with no requirement for electrical energy except for a relatively small value required for inducing a directional torque on the chain of magnetosomes in the cells. Because the energy required to generate the directional torque is independent on the population of MTB being involved but the displacement force can be scaled up with the use of a larger swarm while the total workspace would typically be at microscale dimensions, the energy required for the coils configuration around such workspace and responsible for generating the directional torque can be reduced further to a very low level and hence, makes the implementation of mass-scale bacterial micro-assembly systems, a viable approach. Based on these findings, we propose a corresponding mass-scale system based on many workspaces, each relying on a swarm of MTB to perform micro-assembly tasks in parallel.