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.