Scientists worldwide have been looking at ways to treat various diseases using miniature robots over the last few years. These robots would be able to replace complicated and invasive surgeries such as opening up clogged arteries or delivering medicine to specific locations in the body.
A scientist from EPFL named Selman Sakar along with Bradley Nelson and Hen-Wei Huang from ETHZ worked together to create a method to build these robots, which are equipped with advanced features. At the same time they also developed a testing platform for multiple designs and examined various types of locomotion. As a result they were able to put together microrobots that were both complex and reconfigurable. The manipulation platform was also built to control the robots remotely through electromagnetic fields and allow them to shift their shapes by using heat.
These robots don’t run on motors, and are soft and flexible since they have been made with magnetic nanoparticles and biocompatible hydrogel. The nanoparticles make the microrobots swim and move during the application of an electromagnetic field and also give them their particular shape when they are being manufactured.
Building a microrobot is quite a complex procedure involving many steps. To begin with the nanoparticles are put inside biocompatible hydrogel layers. After that the electromagnetic field is used to get the nanoparticles oriented in different places and then the hydrogel is solidified using a polymerization technique.
The next step is to place the robot in water so that the microrobot’s final 3-D architecture is formed. During this process the robot will fold according to the layout of the nanoparticles that are in the gel.
Once this has been completed the robot is made to swim using an electromagnetic field. The robot will unfold and change its shape once it has become heated. Fabricating the robot in this way gave the researchers the chance to build a specific microrobot that could act the same as the bacterium that’s known to cause sleeping sickness, also known as African trypanosomiasis. This bacterium is propelled by a flagellum but once inside the bloodstream a survival mechanism turns on and hides it away.
In order to get the right microrobot that would mimic this bacterium directly the researchers had to do a lot of testing. The robot prototype that they developed also has a flagellum allowing it to swim and the flagellum can also wrap itself around the body of the robot to remain hidden.
According to Sakar, both the flagellum and the body of the bacterium play an important part in its movement. This new method of production allows the researchers to find the best capability for motion and test various combinations and shapes. This research provides more insight into bacteria movement and how changes occur. Microrobots are still developing and more research is required to monitor any side effects that may occur in patients.
Study has been published in Nature Communications titled “Soft micromachines with programmable motility and morphology”.