Penn State Researcher Patents New Portal to Detect Explosives

August 23, 2000

University Park, Pa. -- A Penn State researcher has patented a new explosives detection device similar in appearance to the metal detection portals passengers are asked to step through at airports.

The inventor, Dr. Gary Settles, professor of mechanical engineering and director of Penn State’s Gas Dynamics Laboratory, says the new portal could potentially also detect trace amounts of illegal drugs as well as chemicals that can be used in weapons, bombs or other contraband.

The portal samples the "human thermal plume," a layer of warm air that surrounds and ascends from a person’s entire body. The air in the plume, heated by the skin, rises naturally from the ankles, legs and torso, creating a boundary layer that moves constantly upward and flows off the top of the head and shoulders. The plume carries in it microscopic flakes of a person’s skin, and other particles, bearing trace amounts of the materials with which the person has been in contact.

The thermal plume moves constantly upward and every surface of the body contributes to it. So, no matter where a person tried to conceal explosives or other contraband, traces would appear in the buoyant airstream that eventually rises above the body in the thermal plume. Normal clothing does not significantly interfere with the process.

"We think of this approach as an elegant natural solution to the problem of sampling airborne trace materials from the human body, " Settles says.

Right now, a breadboard portal, developed with and built by Ion Track Instruments of Wilmington, Mass., can perform an analysis in 10 seconds, he adds. When a person steps into the portal, a blower at the top pulls the thermal plume into a funnel where it contacts a special trap that collects the particles in it. Any vapors from the plume also condense there. The trapped material is then analyzed by Ion Track’s patented ion trap mobility spectrometer (ITMSâ ). Explosives and other chemicals that contain nitrates (NO groups) are detectable now. The device differentiates among explosives including EGDN, RDX, TNT, NG and PETN.

Combining the portal with a metal detector would enable airport personnel, for example, to check passengers for bombs and explosives at the same time that they are being checked for guns and knives.

The portal is currently undergoing preliminary testing under field conditions. The tests are expected to be complete by the end of August when first phase production will begin.

The Penn State researcher notes that the technology, in principle, could be used to detect smuggled money, narcotics, chemical or biological warfare agents, radioactive materials and other hazardous agents. In addition, Settles is exploring the potential to use the portal as a simple, quick, non-intrusive test for diabetes, gangrene, some skin disorders, tuberculosis, and some cancers based on biological signals sampled from the human thermal plume.

Research on the use of the human thermal plume in detection devices, which Settles has had underway since 1993, is supported by grants from the Federal Aviation Administration. The invention is described in patent 6,073,499. Ion Track Instruments has exercised an option to exclusively license this patent for security applications.

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Contacts:

Barbara Hale (814) 865-9481 (o)/ (814) 238-0997 (h)

Vicki Fong (814) 865-9481 (o)/ (814) 238-1221 (h)

Editors: Dr. Settles is at (814) 863-1504 or by email. You also can contact Lori Dodson, manager of the Gas Dynamics Laboratory, at (814) 865-6961 or e-mail

Also see http://www.me.psu.edu/psgdl