Scientists Develop Remote-Controlled “Microrobots” for Medical Procedures

Microscopic structures look and move like bacteria

For the past few years, scientists around the world have been studying ways to use miniature robots to treat a variety of diseases. The robots are designed to enter the human body, where they can deliver drugs at specific locations or perform precise procedures, such as clearing clogged arteries.

Scientists at the Ecole Polytechnique Federale in Lausanne, Switzerland, have developed a method for building tiny bio-inspired “robots” that look and move like bacteria. The scientists have also created a platform for testing several robot designs and different modes of locomotion. Their research was published in Nature Communications.

Unlike conventional robots, these “microrobots” are soft, flexible, and motor-less. They are made of a biocompatible hydrogel and magnetic nanoparticles. These particles have two functions: they give the microrobots their shape during the manufacturing process, and they make them move and swim when an electromagnetic field is applied.

Building a microrobot involves several steps. First, the nanoparticles are placed inside layers of a biocompatible hydrogel. Then an electromagnetic field is applied to orientate the nanoparticles at different parts of the robot, followed by a polymerization step to solidify the hydrogel. After this, the robot is placed in water, where it folds in specific ways, depending on the orientation of the nanoparticles inside the gel, to form the final overall 3D architecture of the microrobot.

Once the final shape is achieved, an electromagnetic field is used to make the robot “swim.” Then, when heated, the robot changes shape and unfolds. This fabrication approach allowed the researchers to build microrobots that mimicked the bacterium that causes African trypanosomiasis, better known as sleeping sickness.

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

For now, the microrobots are in preclinical development. “There are still many factors we have to take into account,” Sakar said. “For instance, we have to make sure that the microrobots won’t cause any side effects in patients.”

Source: EurekAlert; July 22, 2016.