Bomb attacks test U.S. technological ingenuity.

The Army has ordered 330 small robots to help soldiers search for hidden explosives along Iraq's roads.

They are simple contraptions: remote-controlled toy cars outfitted with a pan/tilt camera that can look down and over objects up to three feet tall.

Troops in Iraq have been testing 30 of these so-called Marcbots--or multifunction advanced remote-controlled robots. Their sole mission is to drive down range and scan boxes, bags and guardrails. From a safe standoff range, soldiers can see whether these objects are camouflaged bombs, explained Lt. Col. Lee D. Gazzano, commander of the Army's "Rapid Equipping Force" team based in Iraq.

The REF was created to help expedite the deployment of technologies to the battlefield.

The early version of the Marcbot was prone to breakdowns and its range wasn't long enough. The REF funded improvements to the system and recently ordered 330 robots from Exponent Inc.

The price for a full system is $8,000, which is less than one-tenth the cost of a other military robots currently used in IED sweeps, said Ken Zemach, an engineer at Exponent who spent five months in Iraq as an REF contractor.

"The design itself was driven from our scientists and the soldiers who are living and working in Iraq, not by some R&D lab in the United States," said Zemach. "It also was built with a clear understanding of military logistics and support, and thus runs directly from rechargeable military batteries."

Technologically, it's not a breakthrough, he noted. "It's as off-the-shelf as we could get."

While spending time with U.S. soldiers in Iraq, Zemach was taken aback by the dangerous work these troops were doing. "Soldiers who have to clear the roads for the convoys get out of their vehicles and walk the roadsides, kicking boxes."

Under Army policy, when soldiers see a suspicious object, they must call for an explosive-ordnance disposal unit. "The problem is that there is a box every 100 yards" and not nearly enough EOD units to answer every call.

The use of robots in the search for hidden bombs in Iraq is just one piece of an expanding campaign to mitigate insurgents' devastating attacks that have resulted in hundreds of U.S. deaths and thousands of injuries during the past two years.

"We've seen a migration starting last summer to more complex ambushes," said Army Brig Gen. Joseph L. Votel, director of a special Pentagon agency in charge of developing technologies to defeat improvised explosive devices, or IEDs.

Insurgents camouflage IEDs in places like road signs, he said. "It's a cat-and-mouse game with us.

"More aggressive use of vehicle IEDs is the emerging technique," Votel said. In recent months U.S. vehicles have been targeted with "explosively formed penetrators" that not even armored trucks can protect against. Shaped charges were first developed after World War I to penetrate tanks and other armored equipment. They are used in the oil and gas industry to open up the rock around drilled wells.

Armoring vehicles so far appears to be the only way to stem the casualties, although officials concede that no amount of armor will guarantee survival.

"It's probably not possible to have enough armor to protect everybody with 100 percent surety," said Lt. Gen. Claude V. Christianson, Army deputy chief of staff for logistics.

Armor developers, nonetheless, are striving for improvements. "The enemy tries to counter everything we do," said Col. John Rooney, chief of staff of the Army Test Developmental Command, at Aberdeen Proving Ground, Md.

Engineers at Aberdeen have tested 350 armor technologies from at least 65 vendors during the past two years, Rooney said in an interview.

"Many of the 350 solutions have not performed very well," he said. "Many companies are trying very hard to provide a solution but they don't particularly understand the problem."

While some armor kits protect from IED blasts, they don't shield from shrapnel and fragments, which cause most of the injuries and casualties. "That's clearly something we need solutions for," Rooney said.

In general, said Rooney, softer steel is more effective against fragments, but harder steel may better protect from shaped charges.

Metal armor generally is the most effective against IEDs, although ceramic armor has shown promise. An explosion often causes the ceramic to crack, he said. "It'll stop the first few fragments but when it busts up, the follow on fragments will penetrate. Metals don't break up like that."

To be effective, ceramic plates need special backing material that absorbs the energy of a projective and catches the fragments of both the projectile and the ceramic as it splinters, explained Tim Swinger, vice president of military programs at Honeywell. The company makes the protective fiber known as Spectra Shield, which is used in body armor vests.

He acknowledged that, in the vehicle armor market, the composite systems have to overcome a resistance in the Army to adopt these new technologies, which are perceived as too expensive.

"Throughout the history of Spectra Shield, it's always been an uphill battle of performance versus price," he said.

At Aberdeen, a truck door made of composite armor recently was tested by detonating a Russian 152 mm artillery round place 4 meters away. The door survived, although three pieces of steel penetrated the door's outer panel, said Marc King, vice president of Ceradyne Inc., a supplier of composite armor. Like others in the industry, King said he often gets frustrated by what he described as bias in the Army toward steel armor.

The downside of steel armor is the weight it saddles on a truck. Ceramic armor generally cuts the weight in half, and eventually will be able to compete with steel solutions, said Maj. Gen. Brian I. Geehan, chief of Army transportation. He said ceramic armor will be ready for military use in about two to three years.

Geehan, who heads the Army Transportation School, said the IED attacks have led to substantial changes in the training offered for truck drivers and convoy crews.

"We looked at our basic program of instruction and completely renovated it," he said in an interview. "Every driver will go through convoy live fire in basic training.... Every lieutenant goes through extensive live-fire convoy and weapons training. They learn to shoot different weapons."