Researchers have created tiny ‘microbots’ that are able to move and react in a fashion similar to bacteria, according to a report from the Max Planck Institute for Intelligent Systems.
Bacteria use flagella to move, directed by stimuli like sources of light or the earth’s magnetic field. Researchers have developed synthetic microrobots with motility and phototaxis, mimicking the bacteria’s movement and sense of direction.
“Evolution has taken enormous efforts to endow motile bacteria with the ability to orient themselves,” Max Planck Institute for Intelligent Systems and the University of Stuttgart lead researcher Clemens Bechinger said in prepared remarks.
Nature is too complex to copy directly. “Instead, we are developing microswimmers that are capable of phototaxis with minimal effort,” Bechinger explained.
The microrobots are transparent glass beads, measuring a few thousandths of a millimeter in diameter. One half of each bead is painted with a black carbon layer that heats quickly when exposed to light. The heat separates the surrounding water from the surface. This change causes water to flow from the transparent side to the colored side, moving the bead.
To direct the bead’s movement, the researchers resorted to phototaxis, or movement guided by light. The microparticles are directed along a light gradient to the darker part of the liquid.
“Millions of these microswimmers can be produced with ease,” Bechinger said, according to the Institute. A large number of microrobots could model the swarming behavior of some bacteria. Bechinger also points to the versatility of the bead’s orientation mechanism, saying that it could be controlled by light or by chemical concentration. The team envisions producing microrobots the size of blood cells to patrol, detect, and treat tumors, the Institute reported.