US Army-sponsored researchers have built a land mine detection system for a hundredth of the cost of traditional systems - using parts they bought in online auctions.
A team at the Colorado School of Mines has built a system using microwave-based sensors to detect vibrations in the ground. unlike most current detection systems, the microwave device can see through foliage.
Made from off-the-shelf parts - including some obtained through online auctions - the system costs about $10,000. This compares to $1 million or more for standard laser-based Doppler remote detection systems.
"Land mines are an enormous problem around the world for both military personnel and civilians," says physics professor John Scales.
"We've developed an ultrasound technique to first shake the ground and then a microwave component to detect ground motion that indicates location of the land mine. We hope that the two components together enable us to detect the land mines in a safe fashion, from a distance."
Other low-cost techniques for detecting land mines have included training dogs and even rats to detect chemicals within the explosives. Another approach has even involved the development of biosensor plants that change color when growing in contaminated soil.
"The reason so many people are working on this problem from so many angles," says Scales, "is there is no one scheme that works well all the time. You need an arsenal of tools."