Goal
Microbiorobots (MBRs) are negative photosensitive epoxy (SU-8) microfabricated structures with typical feature sizes ranging from 1 to 100 µm coated with a monolayer of swarmer cells of the bacterium Serratia marcescens. The adherent cells naturally coordinate to propel the microstructures in fluidic environments. MBRs can be controlled using electric fields. Here, an MBR is maneuveured into a microfabricated goal with electric fields. Experiments were performed at Drexel’s BAST lab.
Control
Using computer vision tracking techniques, MBRs can be maneuvered automatically. Using a feedback control algorithm, an MBR is steered along a specified path. The MBR is 40 by 45 µm. Experiments were performed at Drexel’s BAST lab.
Manipulation
Using both light and electric field mechanisms together enables control over the angular orientation as well as two-dimensional positioning of an MBR. A task was assigned of transporting a cube-shaped target load measuring 10 µm on each side using a U-shaped MBR referred to as a transporter, which was positioned and oriented using a combination of bacterial self-actuation, electrokinetics and photoexposure. Experiments were performed at Drexel’s BAST lab.
Sensing
Below, an MBR is used as a mobile sensor. Initially, the MBR rotates due to bacterial actuation and translates due to the coulomb force. As the MBR encounters copper ions, the flagella are disabled, and only the motion due to the coulomb force acts. Experiments were performed at Drexel’s BAST lab.