People have been able to levitate small objects using sound for years. But applications for the technique are severely limited because scientists hadn't figured out how to control and manipulate the floating objects. Until now.
The idea of acoustic levitation is certainly not new. Several levitation methods exist today, including using electrostatic forces, magnetism and light. But each of these techniques has it own drawback. For example, light can only manipulate matter that's very tiny (up to about 50 microns, the size of a human liver cell), whereas magnetic levitation requires the material to have special properties.