The World You Don't See: Electric Auras

Many objects emit an electromagnetic field. You do, I do. Call it an aura, if you like. Even if an invisible field isn't emitted, the presence of an object will affect the shape and strength of a pre-existing electromagnetic field. Peter Weiss, writing for Science News Online, offers an excellent look at the development of electric field sensing and its potential practical applications. If you use a touch screen for your computer or have ever used a stud finder to scan for density differences in a wall, then you have used a device that works by sensing a change in an electric field. However, there are other applications of this kind of wireless sensing, such as detecting the size of a car passenger to determine whether or not an airbag should be fully deployed. Look for fun uses of electric field sensing, too, in the form of games and musical instruments.
Jacobson's Organ & the Sixth Sense | Weird Science