Bombs away — detecting explosive devices

Detecting landmines, IEDs, backpack bombs and other homemade explosives is an area of growing importance in which law enforcement and military forces struggle to keep up with developments, as sniffer dogs and spectrometers can only do so much.

A team from the University of Queensland (UQ) is developing a new sensor for explosive devices using state-of-the-art dendrimers. Dendrimers are macromolecules consisting of a core surrounded by branched structures that are highly flexible with applications in various optoelectronic fields, including solar cells, image sensors, light-emitting diodes and chemical sensors.

Dr Paul Shaw, from UQ’s School of Chemistry and Molecular Biosciences, has joined forces with commercial outfit Arborescent to create a compact, sensitive unit that detects the vapours given off by explosives. Dubbed Arbsense, the unit uses light-emitting dendrimers to detect explosives without the need for physical contact such as swabbing.

“Hidden explosives and improvised explosive devices (IEDs) represent a constant danger to large public gatherings, transport hubs and land-based military operations,” said Dr Shaw. “Providing security for major international events, such as the G20 Brisbane summit and the upcoming Commonwealth Games in 2018, highlights the important role that detection technologies play in providing security.”

While various technological and operational solutions for detecting explosive devices are currently in use, there is no completely reliable ‘golden bullet’ solution and differing field scenarios each present a unique set of challenges. “There is also an increasing incidence of homemade explosives being discovered by police officers, which potentially places them at grave risk,” said Dr Shaw.

Dr Shaw’s aim has been to “combine selectivity and sensitivity in a device capable of non-contact detection” of the vapours released by explosives, all controlled wirelessly with an android-based device. The team sees potential applications for Arbsense in military operations, airports, marine ports, cargo screening, vehicle screening, oil and gas pipelines, undersea telecommunications and large public events.

This project has been in development since 2009 when Arborescent first teamed up with the Centre for Organic Photonics and Electronics, which is a joint initiative between the UQ’s School of Mathematics and Physics and the School of Chemistry and Molecular Biosciences.

Funding for the development of the Arbsense prototype was provided through the Australian Research Council Linkage program and the resultant technology was a finalist in last year’s Eureka Prize for Outstanding Science for Safeguarding Australia. Further support has been achieved through the Advance Queensland Research Fellowships Scheme.

Image caption: An Arbsense signal change upon detecting explosive vapours. Image courtesy of Dr Paul Shaw.