There’s simple premise behind what Larry Myers does for a living: If you can smell it, you can find it. Myers is the founder of Auburn University’s Institute for Biological Detection Systems, the main task of which is to chase the ultimate in detection devices—an artificial nose. For now, the subject of their research is little more than a stack of gleaming chips tucked away in a laboratory drawer. But soon, such a tool could be hanging from the belts of police, arson ( 纵火 ) investigators and food-safety inspectors. The technology that they are working in would suggest quite reasonably that, within three to five years, we’ll have some workable sensors ready to use. Such devices might find wide use in places that attract terrorists. Police could detect drugs, bodies and bombs hidden in cars, while food inspectors could easily test food and water for contamination. The implications for revolutionary advances in public safety and the food industry are astonishing. But so, too, are the possibilities for abuse; Such machines could determine whether a woman is ovulating ( 排卵 ), without a physical exam-or even her knowledge. One of the traditional protectors of American liberty is that is has been impossible to search everyone. That’s getting not to be the case. Artificial biosensors created at Auburn work totally differently from anything ever seen before. Aroma Scan, for example, is a desktop machine based on a bank of chips sensitive to specific chemicals that evaporate into the air. As air is sucked into the machine, chemicals pass over the sensor surfaces and produce changes in the electrical current flowing through them. Those current changes are logged into a computer that sorts out odors based on their electrical signatures. Myers says they expect to load a single fingernail-size chip with thousands of odor receptors ( 感受器 ) , enough to create a sensor that ’ s nearly as sensitive as a dog ’ s nose.