Scientists, including those of Indian origin, have developed a novel sensor - inspired by hairy, flying insects - that can quickly and accurately detect a broad range of dangerous airborne chemicals. Most insects have tiny hairs on their body surfaces, but it is not clear what the hairs are for.
Trying to make sense of what these hairs may be capable of, researchers including Arindam Phani and Thomas Thundat from the University of Alberta in Canada designed experiments involving a "forest" of tiny hairs on a thin vibrating crystal chip.
"When using resonators as sensors, most people want to get rid of dissipation or friction because it is considered highly undesirable, it tends to obscure what you are trying to measure. We have taken that undesirable thing and made useful," said Vakhtang Putkaradze, from University of Alberta.
"Sensing chemicals without chemical receptors has been a challenge in normal conditions. We realised that there is a wealth of information contained in the frictional loss of a mechanical resonator in motion and is more pronounced at the nanoscale," said Thundat.
"With the nanostructures, we can feel tiny changes in the air surrounding the resonator. This sensitivity makes the device useful for detecting a wide variety of chemicals," said Putkaradze.
"Similar mechanisms involving motions of nano-hairs may be used for sensing by living organisms," said Phani. Since the friction is changing dramatically with minute changes in the environment and is easy to measure, it may be possible to eventually produce a gadget of the size similar to or slightly larger than a Rubik's cube and designed to plug into a wall.
At present, the group's device is geared primarily to sensing chemical vapors in air. The researchers think that this device can work like a smaller and cheaper spectrometer, measuring chemicals in the parts-per-million range. They believe that apart from size and reasonable cost, what sets the device apart from larger and more expensive equipment is its versatility.
The sensor is not directed to detect any specific chemical, so it can interpret a broad range, and it does not require attaching the molecules to anything to create a mechanical response.
