Microscopic Robot Heads for Surgery
- Not quite the nanobots that Kurzweil's future portends, but it's one
step closer. The full article with images and a video can be found
I include the text of the article without images:
By Tracy Staedter, Discovery News
Aug. 26, 2005 A new microscopic robot that it is so small it can be
injected into the body through a syringe could one day be used by
doctors to analyze medical conditions, deliver drugs or perform
minimally invasive surgery.
The biomedical micro-robotic system, developed by a team of
scientists from the Swiss Federal Institute of Technology in Zurich,
Switzerland, is the smallest of its kind with machined and assembled
parts, and has been demonstrated to successfully maneuver through a
watery maze using external energy from magnetic forces.
The minimally invasive robot is particularly well-suited to navigate
through the blood vessels of the heart or the fluids located behind
the eye and in the ear to diagnose and treat disease, resulting in
less injury and a faster recovery time for patients.
"The application we're actively considering is eye surgery in which
these devices are guided inside the eye toward the retina by a
surgeon to inject drugs in retinal veins that are about the size of a
human hair," said team leader Brad Nelson, professor of robotics and
Barely a speck of a robot, the smallest devices Nelson and his team
have built are about four hair-widths long and are made up of several
The mechanical and electrical parts are cut and etched from pieces of
nickel and assembled using methods similar to those used to design
and make computer chips.
Unlike most mobile robots that either have a battery on board or are
connected to an electric cable to drive its motors, this robot's
power comes from an external magnetic field generated by a machine.
The magnet acts to align and pull the robot lengthwise, which because
of its elongated shape behaves like a magnetized needle one tip has
a positive charge and the other tip has a negative charge.
"If it's dragging a tether behind it, it's a more complicated system.
You have to worry about what might prevent the robot from getting to
its destination," said mechanical engineer Rajesh Rajamani, an
associate professor at the University of Minnesota.
"Here, on the other hand, those things are all absent; that's why you
are able to make the robot small."
In addition to being tiny, the robot has movable mechanical
components designed to be tuned to specific magnetic frequencies.
Just as turning a dial on a radio will tune in a different station,
switching to a different frequency in the micro-robotic system
vibrates a different mechanical part on the device.
For example, tuning to a 2 kilohertz frequency could vibrate a motor
that extends a small syringe into a blood vessel. Tuning to 3
kilohertz could drive a pump that delivers drugs into the vessel.
In lab experiments, the team successfully steered the micro-robot
backward and forward through a water-filled maze that has channels
about as wide as 10 human hairs and as deep as three hairs.
Their results help illustrate which magnetic fields strengths work
best to steer the robot through different bodily fluids.
The findings will be reported for the first time at the Eighth
International Conference on Medical Image Computing and Computer
Assisted Intervention in October.