FINDING explosives, weapons, drugs and illegal immigrants concealed in cargo containers will be made easier by a new type of robot being developed in the UK that can detect tiny particles of illegal substances, or human activity, and raise the alarm.

It will be the world's first cargo-screening device able to pinpoint all kinds of illicit substances and the first designed to operate inside standard freight containers.

Nicknamed the "cargo-screening ferret" and designed for use at seaports and airports, the device is being worked on at the University of Sheffield with funding from the Engineering & Physical Sciences Research Council.

The robot will be equipped with a suite of sensors that are more comprehensive and more sensitive than any currently employed in conventional cargo scanners.

Recent advances in both laser and fibre-optic technology now make it possible to detect tiny particles of different substances. The project team is developing sensors that incorporate these technologies and that are small enough to be carried on the 30cm-long robot, in order to detect the specific "fingerprint" of illegal substances at much lower concentrations than is now possible.

When placed inside a steel freight container, the ferret will attach itself magnetically to the top, then automatically move around and seek out contraband, sending a steady stream of information back to its controller.

Current cargo-screening methods rely on a variety of separate methods, such as the use of sniffer dogs and external scanners for detecting explosives and drugs, as well as carbon dioxide probes and heartbeat monitors to detect a human presence.

Cargo scanners in use at seaports and airports only generate information on the shape and density of objects or substances. The ferret will be able to provide information on what they consist of as well.

"It is essential we develop something which is simple to operate and which border agents can have total confidence in," said Dr Tony Dodd, who is leading the project at Sheffield. "The ferret will be able to drop small probes down through the cargo and so pinpoint exactly where contraband is concealed."

Working prototypes of the cargo-screening ferret could be ready for testing within two years, with potential deployment within five years.

The ferret will also offer great advantages in combating human trafficking. Currently, it is very difficult to detect people hidden in freight containers; the use of x-rays is prohibited because of the harm the radiation could do to anyone concealed there. Sensors on the ferret will be able to "sniff" tiny traces of carbon dioxide that indicate the presence of people hidden in the containers.

Another key benefit is that the ferret will reduce the need for customs and security officials to enter or unpack freight containers

This is time-consuming and may expose officers to danger or possible contamination by harmful substances.

The project also involves the University of Glasgow, Loughborough University, City University London, and defence and security specialists QinetiQ. The idea for the project emerged from an event organised by the Engineering & Physical Sciences Research Council (EPSRC), the Home Office Scientific Development Branch and the UK Borders Agency.