Sensor hitches a ride

Researchers at Sandia National Laboratories and Lockheed Martin have created a half-ounce sensor designed to ride on aerial drones to detect gas attacks on cities and military bases.

A half-ounce ‘sniffer’ intended to ride on small aerial drones to detect possible gas attacks on cities and military bases has been created by researchers at Sandia National Laboratories in partnership with Lockheed Martin.

The patented device, which detects nerve gases and blister agents, operates on only half a watt of electrical power, claims Sandia researcher Doug Adkins.

While other gas monitors exist, ‘this is small, lightweight, low power, and offers rapid analysis,’ said Adkins. ‘Rapid analysis currently is not possible with any other package near this size.’

Immediate analysis is critical in warning an endangered population of an attack or in surveying sites after alleged incidents.

Discussions are underway with a US company that produces drone aircraft to include the device among sensors designed to detect biological and radiological threats.

The device also has possibilities for use in or near the ventilation systems of buildings, or, with addition of a small pump, on posts surrounding military bases.

Called SnifferSTAR, the invention consists of a series of tiny sensors sat on a small, oblong platform, atop a microprocessor board smaller than a credit card. The forward motion of the vehicle forces air through the device.

Material in the sampled air is absorbed and concentrated. It is then thermally released (desorbed) to pass over thin stripes of coating materials, to which it temporarily sticks.

The coating stripes are located on a quartz surface that vibrates at pre-set frequencies when minute amounts of electricity pass through it. The mass of incoming stuck particles changes the frequencies of the vibrations of each stripe.

The altered frequency data is passed to a processing unit on the SnifferStar module. The data is then relayed to a processor on the drone or radio-linked to a main data processor on the ground. The information is automatically compared against a library of the patterns created by a range of gases.

‘We have very few false positives,’ said Doug. ‘The device ignores most common interferents.’

The sampling process is repeated every 20 seconds, with 15 seconds intake and five seconds for analysis. The inrush of air then clears the device sensors for the next reading.