The end is looming: microrobots will take over the world. Over the last few years, major advances in microbotics research have yielded results that could change the direction of technological advancement. Microrobotic technologies have been combined with biological applications that can essentially act as mini superheroes in the human body. The biological applications of these microrobots are so far-ranging; they could both revolutionize tissue engineering and act as drug carriers.
For instance, researchers at École Polytechnique de Montréal, supervised by Professor Sylvain Martel, used swimming bacteria along with microscopic beads to make a self-propelling “nanobot.” Unlike other research combining micro-sized particles with bacteria, Professor Martel’s group created a hybrid that could be externally controlled using MRI imaging. To achieve this breakthrough, a rather simple design was implemented. A specific group of bacteria with magnetic particles naturally embedded in their anatomy acted as a “magnetic compass needle” that could be controlled by the MRI instrument’s external magnetic field. Using a modified set-up, that included the MRI machine, the surrounding magnetic field was used to direct the bacteria to swim in any direction the researchers wanted. Interestingly, this class of bacteria was found to be faster and stronger than other types while still small enough to fit into the smallest of blood vessels (measuring about 2μm)!
The major application foreseen by this research is the use of the bacteria as carriers for chemotherapeutic drugs. A significant nanobot-related publication by this research group describes the use of the MRI machine to directly steer various microorganisms within the carotid artery of a living pig. Such microorganisms include naturally magnetic bacteria, bacteria with magnetic microbeads, and magnetic microbeads with artificial flagella. The group plans to further their research by introducing a magnetically-steered microvehicle to carry the nanobots through major arteries toward the target tissue. This was introduced to combat the issue of nanobot strength against the blood current in major blood vessels. The goal of this research is to inject a microvehicle containing the nanobots into large blood vessels after which it would be controlled externally by the MRI machine to move closer to the target tissue. Near the destination, the microvehicle would disintegrate while the nanobots are released and directed towards the target tissue.
A more recent research breakthrough concerning microrobots occurred when researchers from University of California, Berkeley, Duke University and Dartmouth College collaborated in a research paper to describe the method in which a group of microrobots’ movements could be controlled by one electric signal. This method was implemented in such a way that the microrobots could self-assemble into larger structures on command. The previous statement may not be awe-inducing right now but, hopefully, the following analogy will help motivate the appropriate response: think of the individual Power Ranger robots that become a Mega Power Ranger robot in the face of particularly vicious villain. While such a manipulation by itself is pretty cool, the applications of this technology are broader than just fighting rogue villains. For one, this technology can be used in anything from tissue engineering to chip manufacturing.
The major difference of this technology relative to similar efforts by other research groups is that this group used an electrostatic potential sent through an electric-array surface to move the robots. While other groups have used magnetism to control microrobot movement, Professor Bruce Donald at Duke University used this electrostatic system to tweak each robot to respond with a different action to the voltage sent through the array. Therefore, the collection of small actions can result in a complex structural formation. While the majority of robot formations are currently simple, this technology could be extended so that microrobots eventually circulate the bloodstream, coagulate at the target tissue and build or repair the tissue structure. The defining feature of these microbots, their extended arms, allows the robots to move forward and make turns with precision. The advantages to this technology include its compact nature, the power administration via the electrodes on the arrays itself and the small set-up needed to control the robots (compared to magnetic microrobots). The next step in this research is to move the setup to a liquid environment with the hope that these robots will be able to assemble components of biological tissue-mimicking natural processes inside the body.
These breakthroughs in microrobotics indicate that the applications will not only be groundbreaking but will have widespread impact to all areas of science and technology. If microbots have that kind of influence on our daily lives in the future, you could say that these robots will eventually become so ingrained that microrobots will have, essentially, taken over the world.