Current bomb-detection methods are by no means perfect. They often require bulky machinery and a complicated process of sample preparation that has to be performed by a trained professional.
They use a technique called ‘mobility spectrometry’, which identifies molecules in explosives depending on how fast they’re moving through an electric field, but this technique has so far only been able to detect a handful of explosive types, and only if they are at relatively high concentrations.
Plus, according to Sarah Zhang at Gizmodo, these machines can detect traces of dangerous chemicals at concentrations of parts per billion, which sounds pretty good, but a billion isn’t enough when we’re dealing with explosives. We need parts per QUADRILLION, which is a million times better.
Enter the new bomb-detecting nanochip, developed by researchers from Tel-Aviv University in Israel. Not only is this nanodevice entirely portable, it can identify several different types of explosives in real time, and from several metres away, even if those explosives have been deliberately masked by stronger chemicals.
Still in the prototype stage, the chip was built using clusters of nano-sized transistors that are extremely sensitive to certain types of chemicals. When these chemicals come into contact with the transistors, they cause changes in the electrical conductance, which tips off the device.
This small chip is inspired by how our own olfactory systems work. We have a finite number of smell receptors in our noses but can distinguish between a seemingly infinite number of smells based on how different receptors differentially bind the molecule. Likewise, the chip has eight different nano-sized chemical receptors. Depending on how molecules bind each of these eight receptors, the chip can tell whether they’re innocent or indicative of a bomb.”
The device has been tested using several common types of explosives, including TNT, RCX and HMX, which is used by the military and in commercial blasting operations, plus peroxide-based explosives like TATP and HMTD, which are often used in home-made bombs. These two in particular have really tested current detection methods. The chemicals were detected in “highly contaminated” conditions designed to mask their presence, such as in the presence of heavy cigarette smoke.
According to Phys.org, the TATP particles could be detected at a distance of five metres from the source, and TNT at four metres away. Only five seconds of air sample collection was required to detect the dangerous chemicals.
And while all of this sounds pretty promising, there’s one – rather large – problem. With such incredible sensitivity, there’s a real risk that this device will pick up trace amounts of chemicals on the clothes of innocent people, potentially causing even more hold-ups in airport security lines. Which is the last thing anyone needs. This is something the researchers will need to figure out before we see this nanochip move over into the commerical space.