Dartmouth College Office of Public Affairs • Press Release
Posted 09/14/05 • Contact Sue Knapp (603) 646-3661
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. (view images of the microrobot)
Donald, right, and Igor Paprotny display models of their microrobot
that are 1,000 times their 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, the Joan P. and Edward J. Foley Jr. 1933 Professor of Computer Science at Dartmouth, report their creation in a paper that will be presented at the 12th International Symposium of Robotics Research in October in San Francisco, which is sponsored by the International Federation of Robotics Research. A longer, more detailed paper about this microrobot will also appear in a forthcoming issue of the Journal of Microelectromechanical Systems, a publication of the IEEE, the Institute of Electrical and Electronics Engineers.
tens of times smaller in length, and thousands of times smaller in mass
than previous untethered microrobots that are controllable," says
Donald. "When we say 'controllable,' it means it's like a car; you can
steer it anywhere on a flat surface, and drive it wherever you want 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."
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; or involving biotechnology, say to
manipulate cells or tissues.
Donald worked with
Christopher Levey, Assistant Professor of Engineering and the Director
of the Microengineering Laboratory at Dartmouth's Thayer School of Engineering, Dartmouth 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.
paper describes a machine that measures 60 micrometers by 250
micrometers (one micrometer is one thousandth of a millimeter). It
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.
who earned a Ph.D. in Computer Science working on this project in
Donald's lab, adds, "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, these
robots 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.
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 explains 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 is 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).