Chemotactic steering of bacteria propelled microbeads
Flagellated bacteria have been embraced by the micro-robotics community as a highly efficient microscale actuation method, capable of converting chemical energy into mechanical actuation for microsystems that require a small payload and high rate of actuation. Along with being highly motile, Serratia marcescens (S. marcescens), our bacterium species of interest, is a highly agile biomotor capable of being steered via chemotaxis. In this paper, we attached S. marcescens bacteria to polystyrene microbeads towards creating biohybrid that can propel themselves towards an attractive chemical source. Using a three-channel microfluidic device, linear chemical gradients are generated to compare the behavior of bacteria-propelled beads in the presence and absence of a chemoattractant, L-aspartate. We tested and compared the behavior of three different bacteria-attached bead sizes (5, 10 and 20 μm diameter) using a visual particle-tracking algorithm, and noted their behavioral differences. The results indicate that in the presence of a chemoattractant, the S. marcescens-attached polystyrene beads exhibit a clear indication of directionality and steering control through the coordination of the bacteria present on each bead. This directionality is observed in all bead size cases, suggesting potential for targeted payload delivery using such a biohybrid micro-robotic approach.
KeywordsS. marcescens Micro-robotics Chemotaxis Bacterial propulsion
The authors of this paper would like to thank the members of the NanoRobotics Laboratory at Carnegie Mellon University for their help and discussions. We would also like to thank Joseph Suhan of Carnegie Mellon University for help in SEM imaging. This work was supported by the NSF CPS-Medium project (CNS-1135850).
(MP4 2885 kb)
- B. Behkam and M. Sitti, Proc. IEEE Int. Conf. Robot., 1022 (2009)Google Scholar
- B. Behkam and M. Sitti, Proc. IEEE-RAS-EMBS International Conference on Biomedical Robotics and Biomechatronics, 753 (2008)Google Scholar
- S.-Y. Cheng, S. Heilman, M. Wasserman, S. Archer, M.L. Shulerac, M. Wu, Lab on a Chip 7(763) (2007)Google Scholar
- E. Diller, S. Floyd, C. Pawashe, M. Sitti, IEEE Trans. on Robotics 28, 172 (2012a)Google Scholar
- E. Diller, S. Miyashita, M. Sitti, RSC Advances 2, 3850 (2012b)Google Scholar
- E. Diller, C. Pawashe, S. Floyd, M. Sitti, Int. J. Robot. Res. 30, 1667 (2011)Google Scholar
- B. Donald, C. Levey, C. McGray, I. Paprotny, D. Russ, J. Microelectromech. S. 15 (2006)Google Scholar
- S. Floyd, E. Diller, C. Pawashe, M. Sitti, Int. J. Robot. Res. 30, 1553 (2011)Google Scholar
- D. Kim, A. Liu, and M. Sitti, Proc. IEEE/RSJ Int. Conf. Robots and Intelligent Systems, 1674 (2011)Google Scholar
- C. Pawashe, S. Floyd, E. Diller, M. Sitti, IEEE Trans. on Robotics 28, 467 (2012)Google Scholar