Sensor network could detect trace quantities of explosives

An ambitious project to develop a city-wide network of autonomous sensors that can detect trace quantities of airborne explosives has been announced.

The €4m (£3.49m) European Union (EU)-funded BONAS (Bomb Factory Detection by Networks of Advanced Sensors) project was brought about in response to the 2005 London bombings.

The partnership, led by the Italian National Agency for New Technologies, involves scientists from King’s College London, Queen’s University Belfast, the Scientific Police Institute at Lausanne University in Switzerland and the Finnish National Bureau of Investigation.

Anatoly Zayats, professor of biophysics and nanotechnology and project lead of the King’s team, spoke to The Engineer about the project.

‘The goal is to develop a network that will be based on different types of sensors — different technologies — and the data from these sensors will be cross-checked to avoid false alarms and to increase sensitivity.

‘There is no well-defined approach for this at the moment. The problem is that, even with big machines in airports, they’re just not sensitive enough to detect trace airborne particles.’

His team will use its expertise in a laser technique called Raman scattering, which can detect the ‘chemical fingerprints’ of compounds by observing small changes in the colour of light when it interacts with the chemical bonds.

The team has demonstrated its technology in a controlled laboratory environment to detect quantities down to a single molecule; however, the equipment used is still based on large, table-top detectors.

‘The question is how to translate these technologies into something that is scalable, cheap and viable for deployment in challenging environments,’ Zayats said.

He added that he was nevertheless confident of developing a prototype sensor that would be ready for testing in the field within two years. The first application of any resulting commercial technology might be in mobile sensors for police.

‘It could be used either for early warning, before sending in police — or if there is suspicion the device can be deployed straight away to assess whether there are indeed explosives present,’ Zayats said.

The ultimate aim will be for city-wide coverage across the transport network, sensitive buildings and structures, with data fed back to a central command station for analysis and early warning.