Microbot is controllable and untethered
In a world where "supersize" has entered the lexicon, there are
some things getting smaller, like cell phones and laptops. Dartmouth
researchers have contributed to the miniaturizing trend by creating the world's
smallest untethered, controllable robot. Their extremely tiny machine is about
as wide as a strand of human hair and half the length of the period at the end
of this sentence. About 200 of these could march in a line across the top of a
plain M&M.
Bruce Donald (right) and Igor Paprotny display models of their microrobot that
are 1,000 times actual size. To illustrate how small these machines are, the
white disk represents a cross section of a human hair. (photo by Joseph Mehling
'69)
|
The researchers, led by Bruce
Donald, Joan P. and Edward J. Foley Jr. 1933 Professor of Computer Science, reported their
creation in a paper that will be presented in October at the 12th International Symposium of Robotics
Research in San Francisco, which is sponsored by the International Federation of Robotics Research.
A longer, more detailed paper will appear in a forthcoming issue of the Journal
of Microelectromechanical Systems, a publication of the Institute of Electrical
and Electronics Engineers.
"It's tens of times smaller in length, and thousands of times smaller
in mass than previous untethered microrobots that are controllable," said
Donald. "When we say 'controllable,' we mean you can steer it anywhere on
a flat surface, and drive it wherever you want it to go. It doesn't drive on
wheels, but crawls like a silicon inchworm, making tens of thousands of
10-nanometer steps every second. It turns by putting a silicon 'foot' out and
pivoting like a motorcyclist skidding around a tight turn."
The future applications for micro-electromechanical systems, or MEMS,
include ensuring information security, such as assisting with network
authentication and authorization; inspecting and making repairs to an
integrated circuit; exploring hazardous environments, perhaps after a hazardous
chemical explosion; and biotechnology, possibly to manipulate cells or
tissues.
Donald worked with Christopher
Levey, Assistant Professor of Engineering and the Director of the Microengineering
Laboratory at Thayer
School of Engineering, Ph.D. students Craig McGray and Igor Paprotny and Daniela
Rus, Associate Professor of Electrical
Engineering and Computer Science at the Massachusetts Institute of Technology.
Their paper describes a machine that integrates power delivery, locomotion,
communication and a controllable steering system-the combination of which has
never been achieved before in a machine this small. Donald explains that this
discovery ushers in a new generation of even tinier microrobots.
McGray, who earned a Ph.D. in Computer Science working on this project in
Donald's lab, added, "Machines this small tend to stick to everything they
touch, the way the sand sticks to your feet after a day at the beach. So we
built these microrobots without any wheels or hinged joints, which must slide
smoothly on their bearings. Instead, they move by bending their bodies like
caterpillars. At very small scales, this machine is surprisingly fast."
McGray is currently a researcher at the National
Institute of Standards and Technology in Gaithersburg, Md.
The prototype is steerable and untethered, meaning that it can move freely
on a surface without the wires or rails that constrained the motion of
previously developed microrobots. Donald explained that this is the smallest
robot that transduces force, is untethered, and is engaged in its own
locomotion. The robot contains two independent microactuators, one for forward
motion and one for turning. It's not pre-programmed to move; it's teleoperated,
powered by the grid of electrodes it walks on. The charge in the electrodes not
only provides power, it also supplies the robot's instructions that allow it to
move freely over the electrodes, unattached to them.
The work was funded in part by the Department of Homeland Security,
Office of Domestic Preparedness through Dartmouth's Institute for Security Technology
Studies (ISTS).
By SUSAN KNAPP
|
RSS/XML Feed