Savvy sensor

Using lasers and tuning forks, researchers at

have developed a chemical weapon agent sensing technique that could exceed current and emerging chemical detection requirements. The technique, called Quartz Laser Photo-Acoustic Sensing (QPAS), is now ready for prototyping and field-testing.

PNNL, a US Department of Energy national laboratory, has demonstrated QPAS’s ability to detect gaseous nerve agent surrogates. In one test, researchers used diisopropyl methyl phosphonate (DIMP), which is a chemical compound similar to sarin. QPAS detected DIMP at the sub-part-per-billion level in less than one minute. The miniscule level is similar to letting one drop of liquid DIMP evaporate into a volume of air that would fill more than two Olympic-size swimming pools.

‘QPAS is an extremely sensitive and selective chemical detection technique that can be miniaturized and yet is still practical to operate in field environments,’ said Michael Wojcik, a research scientist at PNNL. ‘The laser, tuning fork and other technology needed for QPAS are so simple, and yet robust, that further development is a low-risk investment, and we’re eager to take it to the next level.’