BOSTON — Timothy Swager began developing bomb-sniffing technology a decade ago under a Pentagon-funded research project to help detect land mines — a use for which Swager's invention has yet to see action in many of the world's war zones.

Instead, U.S. soldiers in Iraq are using Swager's hand-held device to scan people and automobiles for traces of bomb-making materials or for hidden explosives that can be detected through telltale chemical vapors.

Soldiers also are using robots with Swager's sensing equipment to find explosives in hard-to-reach and dangerous areas.

Financial obstacles, rather than technical ones, have so far prevented the invention's use in helping pinpoint the location of old land mines, Swager says.

So he's pleased it's found applications in Iraq that the military credits for saving lives.

"Troops were getting killed, and they needed everything they could get their hands on," Swager said. "That really catapulted this technology forward."

Swager's work in developing explosives-sniffing technology and other inventions earned the 45-year-old chemist this year's $500,000 Lemelson-MIT Prize, announced yesterday.

Swager, head of the Department of Chemistry at the Massachusetts Institute of Technology, worked with colleagues to invent synthetic material that attracts chemicals such as TNT that are typically used in explosives. The invention is capable of detecting minute traces of explosives at chemical concentrations as low as a few parts per trillion.

In 2001, Swager licensed his patented technology to Nomadics, now a unit of ICx Technologies, for use in that company's Fido Explosives Detector, named for its ability to simulate a bomb-sniffing dog.

The technology can be fitted to military robots produced by two Massachusetts firms: Burlington-based iRobot Corp. and Waltham-based Foster-Miller Inc.

Fido also has been tested by National Park Police who used hand-held units to screen bags on the Mall in Washington, D.C., during last year's Fourth of July celebration.

"I can envision down the road it could be used for airport security screening," he said.

The Lemelson-MIT program also honored Lee Lynd as the winner of its new $100,000 Award for Sustainability, for work that has the potential to improve global quality of life and protect the environment.

Lynd, a professor of engineering at Dartmouth College, received the award for inventions that convert materials such as grass, wood, wheat and rice straw into ethanol for fuel.

Jerome H. Lemelson and his wife, Dorothy, founded the nonprofit Lemelson-MIT Program in 1994.