Micro medical robots inspired by bacteria

The study, published in the journal Nature Communications, explains how the microbots are made using a combination of biocompatible hydrogel and magnetic nanoparticles. An electromagnetic field orientates the nanoparticles, then a polymerisation process is used to solidify the hydrogel. The embedded nanoparticles mean the microbots can be controlled from outside the body using magnetic fields, with different types of locomotion dictated by the robots’ different shapes.

The researchers were inspired by the bacterium that causes African trypanosomiasis, commonly known as sleeping sickness. It uses a slender thread-like structure called a flagellum to propel itself around the body, but then hides it once in the bloodstream as part of its survival mechanism. A range of different designs were tested in order to imitate this behaviour.

"Our new production method lets us test an array of shapes and combinations to obtain the best motion capability for a given task,” said EPFL scientist Selman Sakar. “Our research also provides valuable insight into how bacteria move inside the human body and adapt to changes in their microenvironment."