Quantitative evaluation of bacterium-driven microobject fabricated by optical tweezers

Micro/nano robots have been actively studied to lead the developments of the novel technologies, such as drug delivery systems (DDS) and micro/nano surgery inside human body. Recently, the micro living organisms, especially flagellated bacteria, have been used as the driving forces for the microobjects. To achieve the more precise control of the bacteria-driven microobjects, we previously developed the method to assemble single bacterium onto the microobject using optical tweezers, unlike the conventional random and mass attachment. The assembly of the single bacterium onto the 3 μm microbead using optical tweezers was experimentally demonstrated. And, it was confirmed that the bacterium was attached on the microbead firmly by observing the movement of the fabricated bacteria-driven microbead. In this paper, we quantitatively evaluate the movements of the bacterium-driven microobject fabricated using optical tweezers. The movements of the bacterium-driven microobject and control samples are analyzed using mean square displacement (MSD).