Levitation is no longer living in the realms of magic. A team of Japanese scientists has managed to levitate small particles and moved them around mid-air.

Using ultrasonic levitation, does this mean a tractor beam is possible?
In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that various materials could be manipulated by our proposed method.
Read the whole paper at Arxiv.