Levitation and the defiance of gravity is possible. If until now levitation was just a magic act or circus “reality” or, tractor beam technology existed just in sci-fi movies, recently, a team of Japanese researchers have demonstrated the first technology that not only brings the mythology of levitation to life but leap frogs it to create a tractor beam, lifting and moving objects across 3 dimensions using sound alone.
The essence of levitation technology is the countervailing of gravity. By stoping gravity, levitation is possible. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers.