Holographic acoustic tweezers could be used to create 3D displays

A holographic acoustic tweezers (HAT) system has been used to suspend up to 25 objects in mid-air simultaneously. The feat was achieved by Bruce Drinkwater at the University of Bristol in the UK and Asier Marzo at the Public University of Navarra in Spain, who used a complex array of loudspeakers to create an intricate, controllable field of sound waves. The duo believes that their setup could have important medical applications in the near future,  and could also be used to create physical 3D hologram displays.