14 DAY TRIAL // Researchers at the US Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) have recently been able to exploit a phenomenon that has for a long time stopped electronics manufacturers from doing what they do best in order to create a new class of advanced chemical and biological sensors. The new instrument is capable of detecting extremely small amounts of various compounds in the air, and acts pretty much like a dog's sniffer. The innovation was produced in the laboratory of researcher Panos Datskos, who is the leader of the current efforts.
“While the research community has been avoiding the nonlinearity associated with the nanoscale mechanical oscillators, we are embracing it. In the end, we hope to have a device capable of detecting incredibly small amounts of explosives compared to today's chemical sensors,” explains ORNL Materials Sciences Division Center for Nanophase member Nickolay Lavrik, who was also the co-developer of the new system. The goal here is to make detecting explosives, biological agents and narcotics faster and more efficiently than ever before, the team says.
The researchers add that the new system consists of various components, including imaging optics, a laser, a digital camera, a signal generator, a processor for digital signals, as well as other instruments. Together, they act like an artificial nose, based on micro-scale resonators. These devices are very similar to the microcantilevers used in atomic force microscopes (AFM). This observation technique recently began being explored for producing possible mass and force sensing devices. In spite of the fact that the basic principles are very straightforward – measuring changes in the resonance frequency due to mass changes – there have been many obstacles stopping researchers from constructing such devices until now.
“These challenges are due to requirements of measuring and analyzing tiny oscillation amplitudes that are about the size of a hydrogen atom,” Lavrik says. “In the past, people wanted to avoid this high amplitude because of the high distortion associated with that type of response. But now we can exploit that response by tuning the system to a very specific frequency that is associated with the specific chemical or compound we want to detect,” states Datskos, who is also a ORNL Measurement Science and Systems Engineering Division expert.
“With this new approach, when the microcantilever stops oscillating we know with high certainty that the target chemical or compound is present,” Lavrik adds. The team reveals that, if sufficient funding is secured, a working prototype to demonstrate the new technology could be constructed within 6 to 18 months.