Canines are known for their sensitive sniffers, but now scientists have developed an artificial nose that can operate without chow or regular walks and won't bark at squirrels. Researchers at Tufts University constructed an electronic nose that has about 20 attributes of living noses and their information processing capabilities. While living noses have about 1,000 different chemical receptors for identifying smells, the electronic nose is performing well in preliminary tests of its ability to detect landmines.
By looking for the chemical explosives of landmines, an electronic nose mounted on a robot, for example, promises to work more efficiently than typical landmine detectors that simply look for the presence of metals - a plentiful commodity in battlefields. "Chemical sensing is one way of doing it better, " says Dr. Harold Bright, Program Manager for the E-Nose project at the Office of Naval Research.
The sensor works by picking up air puffed across the E-nose. This sensor can detect changes in odors as well as distinguish a number of odors. Right now the dogs have a slight advantage in "nose-to-nose " tests, but the E-nose is making great strides and "won't get tired, sick or refuse to work" says Bright.
The E-nose uses a family of fluorescent polymers, developed with support from the Office of Naval Research. Polymers are materials containing many tiny building blocks that are linked together to form long chains. Polymers occur in nature in the form of tars and oils, while plastics and non-stick cookware coatings are synthetic polymers. The E-nose polymers are embedded in sensor arrays that generate patterns from the sniffed materials.
Alongside the E-nose, a commercial gene chip company is also using the same Office of Naval Research-funded array technology for DNA gene sequencing. Illumina, Inc., of San Diego, Calif., is creating next-generation diagnostic tools for personalized medicine.