Micro-Robot Big on Promise

Government invention can be used to detect chemical or biological hazards

WEDNESDAY, Dec. 26, 2001 (HealthDayNews) -- It may not be as cute as one of those toy robot dogs, but a micro-robot the size of a June bug may prove a vital tool in detecting chemical and biological contamination resulting from industrial accidents or even terrorist attacks.

The robot, which is small enough to crawl beneath many doors, can be equipped with a swatch for taking samples, or with a special device, known as a microcantilever, that reacts in the presence of a specific chemical.

So instead of humans being sent into dangerous areas or situations, the micro-robot can be used to help assess and determine potential threats or health hazards.

''There are multiple areas where I think it can be applied,'' says creator Venu Varma, a development engineer with the Robotics and Process Systems Division, part of the U.S. Department of Energy's Oak Ridge National Laboratory in Tennessee.

For example, the micro-robot can be sent into warehouses where radioactive or other kinds of hazardous materials are stored to check for leaking containers.

''It can go into areas where you want a non-invasive entry," Varma says.

But he adds it can function only in indoor settings on fairly smooth, even surfaces.

''This is not something that you use on the road or on grass or on a beach, or anything like that," Varma says.

The prototype micro-robot weighs about 2.5 grams and is about a quarter of an inch tall. It has a single rear leg that pushes it forward and also has two non-powered wheels. It moves about 2 feet per minute.

One of the most interesting features of this micro-robot is that the leg is powered by a piezoelectric device instead of a conventional electric motor, Varma says.

Piezoelectricity is created when pressure is applied to certain types of crystals, including quartz. These crystals produce high voltage at low current that's similar to static electricity.

The current model is tethered to a power source, but Varma says he plans to make an independent micro-robot that carries its own battery.

It will be slightly larger than the prototype and will have two legs and one wheel, which will enhance its maneuverability. Because of funding factors, he adds, it will be more than a year before the new version is ready for demonstration.

Varma says he successfully tested his prototype by placing a bottle of mercury in a room and loosening the bottle cap. The robot, with its microcantilever, scooted under a door, into the room and detected the presence of the mercury.

"Other than its size, which is quite small, I think the uniqueness [of this micro-robot] is perhaps the propulsion system," the piezoelectric device, says Steven Schrock, section head at Oak Ridge's Robotics and Process Systems Division.

He says this kind of robot is an ideal stealth snoop to hunt for hazards in dangerous areas and situations.

"You can do it quite easily with a device like this and do it in a non-intrusive way," Schrock says.

What to Do: For more information about many different kinds of robotics, go to the Robotics Information Page at the University of Massachusetts, or Carnegie Mellon University's Robotics Institute.

SOURCES: Interviews with Venu Varma, Ph.D., development engineer; Steven Schrock, Ph.D., section head; both in the Robotics and Process Systems Division, Oak Ridge National Laboratory, Tennessee
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