In the last decades microfabrication techniques have opened up new ways to study dynamics in artificial systems having complex and controllable shapes. In this line of research, the design and fabrication of efficient and self-powered micro-robots has been a very active research topic. Motile micro-organisms like E. coli may provide an optimal solution to generate propulsion in artificial microsystems. Microstructures can be transported when released on a layer of swarming bacteria, suspended in a bacterial bath or covered by surface adhering bacteria. Although it is possible to obtain a net movement in the mentioned cases, the displacement is stochastic and self-propulsion characteristics are hard to reproduce. In the present work we investigate possible design strategies for bio-hybrid micro shuttles having a defined number of propelling light driven bacteria that self-assemble onto precisely defined locations. The final design aims at minimizing friction and adhesion with the substrate while optimizing propulsion speed and self-assembly efficiency. This optimized microrobot will be remotely controlled by dynamic structured light patterns.
So far, it has not been possible to reach the controlled movement of self-propelled microrobots. Since this is the main goal of our project, we plan to optimize the geometry of the microstructure to ensure an efficient loading of cells. Reaching our objective means that the microrobot can be used for transporting large inert objects, for example blood cells, onto specific target areas, which is one of the hardest labors for a micromachine. Additionally, since we will only use light for defining the trajectory of the microrobot, our approach would provide a much more easy way to control and steer microstructures in comparison with other methods.