* FOR PRESERVATION PURPOSES ONLY * Credit: Tim Sandle

Bacteria can be used to power a micro-sized robot by propelling it in a certain direction. This is remarkable enough, but now engineers and microbiologists have managed to fully control the direction and avoid obstacles on the way.

The devices in question are called “bio-robots” and they are essentially a computer chips coated with motile bacteria (motile because they possess flagella, which act as propellers – the bacterium used is called Serratia marcescens). The idea of the bio-chips is to deliver medicine to cells in the human body.

Researchers developed a novel method, using electric fields to help micro bacteria-powered robots detect obstacles in their environment and navigate around them to get to their goal (Drexel.edu)

Researchers at Drexel University have managed to control the movement of the bio-chips to the level of precision needed to target cells with medicine. This is through using electric fields to direct the bacteria within a fluid. This is made possible because the bacteria adhered to the chip possess a negative charge; thereby varying an external charge source, the movement the bacteria take (direction and distance) can be controlled.

Essentially the process uses two perpendicular electric fields that turn the fluid into an electrified grid. By varying the charge, the course and speed alter; to do this requires a precise computer program. The technique has yet to be tried out in a person, but the results are promising enough to pursue this longer-term experimental aim.

As this tiny robots respond by electric fields that bend around static obstacles, bio microrobots can detect the obstructions and adjust their course (Drexel.edu)

The research has been published in IEEE Transactions on Robotics. The research paper is headed “Electric Field Control of Bacteria-Powered Microrobots Using a Static Obstacle Avoidance Algorithm.”