Bacterial propulsion of chemically patterned micro-cylinders

Bacterial actuation is identified as a possible solution to the on-board actuation and powering challenges in mobile micro-robotics, and controlled actuation of microscale objects using various types of bacteria have been previously demonstrated. In this paper spherical-capped cylinders are identified as the optimal platform from the robotics, hydrodynamics, and adhesion stand point. Polymeric sphericalcapped cylinders are microfabricated and tested. To enhance their propulsion efficiency and directionality, a surfactant-based patterning technique is devised to limit the adhesion of bacteria to the flat end of the cylindrical body. The speed of propulsion was observed to be similar in both cases, but patterned micro-cylinders have higher propulsion efficiency since they are traveling at similar speeds using significantly reduced number of bacteria.