electronic smell sensors are being developed by the jpl and a company called znose. since smell is made of parts per billion of air, these have the potential to detect physical compounds that no other sensor can. they are in use to check food for spoilage and luggage for explosives. in the works are systems to test for tuberculosis, bacteria, indoor air quality, lung cancer, land mines, organ transplant compatibility, air and water pollution, biological and chemical weapons, plastics, even illegal drugs better than dogs! soon they will probably be able to test for identity and emotions through smell, or even tell if you’re lying…