news
Technology | DOI: 10.1145/1562164.1562172
Kirk L. Kroeker
medical Nanobots
Researchers working in medical nanorobotics are creating
technologies that could lead to novel health-care applications,
such as new ways of accessing areas of the human body that
would otherwise be unreachable without invasive surgery.

SinCE KarEL CapEK first used the word “robot” in print in a 1920 play, a vast array of autonomous electro- mechanical systems have emerged from research labs, making their way onto production lines for industrial tasks, into toy stores for entertainment, and even into homes to perform simple household jobs. While the bulk of robotics research strives to make robots more useful and more capable of even greater levels of autonomy, several labs are attempting to make robotic systems much smaller. One of the most active areas of such research is medical nanorobotics, an emerging field positioned at the intersection of several sciences.

As a discipline, medical nanorobotics remains young for now, but many scientists are already demonstrating new developments they say will form the foundations for the next major breakthroughs in this area. Such breakthroughs could lead to novel applications that offer new ways of accessing small spaces in the human body that would otherwise be unreachable without invasive surgery.

“Nanorobotics can play a major role in medical applications, especially for target interventions into the human body through the vascular network,” says Sylvain Martel, director of the nanorobotics laboratory at École Polytech-nique de Montréal. “In many types of interventions, medical specialists are lacking appropriate tools to do a good job, and I believe that nanorobotics could bring new methods and tools to these particular applications.”

Recent fabrication, actuation, and steering demonstrations of nanoscale robots represent the first crucial steps toward developing real-world applications for targeted drug delivery and other uses. But researchers say that with

many engineering and medical challenges remaining to be met, clinically usable medical nanobots might be viable only after several more years of work in this area. “I believe that the first real application that will have a huge impact is in targeted cancer therapy, such as delivering therapeutic agents directly to the tumor through the vascular network,” says Martel.

Currently, Martel and his team are focused on developing a medical application designed to target regions inaccessible to traditional catheterization techniques. The platform they created uses magnetic resonance imaging (MRI) for feeding information to a controller that is responsible for steering the nanobots along blood vessels. The nanobots, which consist of magnetic carriers and flagellated bacteria that can be controlled by computer and loaded with therapeutic and sensing agents, essentially serve as wireless robotic arms that can perform remote tasks.

“Unlike known magnetic targeting

methods, the present platform allows us to reach locations deep in the human body using real-time control,” Martel says. Still, he predicts it will take three to five years before the system reaches maturity, meaning complete computer-based control of the propulsion and steering mechanisms.

Another researcher designing a similar approach to controlling nanobots is Metin Sitti, director of the nanorobotics lab at Carnegie Mellon University. Sitti and his team are working on building nanobots for drug-delivery applications. In one recent project, he and his team have used bacteria to move nanoscale robots, which use the chemical energy inside the bacteria and in the environment for propulsion. In addition to this propulsion method, Sitti and his team have experimented with optical and magnetic stimuli to coax the bacteria into decelerating, stopping, and moving again.

But as with other similar projects in this area, Sitti and his team are facing

 

Bacteria

Direction of rotation of the flagella

Polymer disk

Polymer disk

Bacteria

Robot Body

a nanobot created at carnegie mellon university and demonstrated to be functional in real-world experiments. The flagella motion of the bacteria’s cells propel the nanobot, which is controlled by the application of environmental stimuli.