Up until recently, bomb sniffing dogs have been used everywhere from airports to large cities in an effort to discover explosive devices. However, using dogs is not always as effective as it should be. Other techniques involve swabbing the hands of people suspected of handling explosives, but this method can be cumbersome if covering a large group of people or area.
Chemists at Cornell University have come up with a solution: an extremely sensitive polymer that can detect Improvised Explosive Devices, or IEDs.
RDX (research department explosive) is a favored explosive material of many terrorists. It requires a detonator to explode, but when it has been detonated, the resulting explosion is more powerful than TNT. RDX also has a vapor pressure 1,000 times lower than TNT, which means it’s nearly impossible to detect without direct contact with a concentrator (for example, the swabs occasionally used by airport security).
William Dichtel, assistant professor of chemistry and chemical biology at Cornell, along with graduate student Deepti Gopalakrishnan have made a polymer that can quickly determine if RDX is present on a surface or even in the air. The polymer is created in a way that allows it to absorb light and transport the resulting energy throughout its structure. The polymer then later releases this energy as light in a process called fluorescence. If the energy finds a molecule of explosive as it travels through the polymer, it converts into heat instead of light, which causes the polymer to stop glowing. Because of its design, the polymer can sense tiny amounts of explosive. This will allow for an easier identification of people who have recently handled IEDs.
Dichtel said, “one of the goals is to make detectors that can detect not just explosives on someone’s hands, but in the cloud around them. If someone had an IED in their bag, it would be nice to not have to open it.”
The new polymer could be applied to low-cost handheld explosive detectors. These detectors could supplement or even replace bomb sniffing dogs.