Motility steering of bacteriobots using chemical gradient microchannel

In the recent years, several groups focused on the development of bacteria based microrobots (bacteriobots) using microbeads and flagellar bacteria. The bacteriobots will be a promising cancer therapeutic method in the future with drug encapsulation inside microbeads. However, it remains elusive that how to steer the motion of bacteriobots. In this study, we attempted to steer the motion of bacteriobots with the intrinsic bacterial chemotaxis to particular chemicals. Therefore, a new microfluidic channel was designed and fabricated through micro-molding method of hydrogel patterns, which a sustained chemical gradient was investigated using rhodamine B at various determined time intervals. Thereafter, the bacteriobots solution was injected into the central channel with chemoattractant gradient, then the chemotactic motion of bacteriobots was investigated through a microscope and analyzed with MATLAB program. Moreover, some other chemoattractant chemicals, secreted from tumor cells could also stimulate the tumor targeting ability possible with bacteriobots. Overall, the motion of bacteriobots can be steered through bacterial chemotaxis, and we expect drug embedded bacteriobots to be a new targeted therapy in cancer treatment.