"... Science-fiction movies such as Star Wars portray volumetric systems that not only provide visual but also tactile and audible 3D content.

Here, we present a Multimodal Acoustic Trap Display (MATD): a mid-air volumetric display that can simultaneously deliver visual, auditory, and tactile content, using acoustophoresis as the single operating principle. Our system acoustically traps a particle and illuminates it with red, green, and blue light to control its colour as it quickly scans through our display volume. Using time multiplexing with a secondary trap, amplitude modulation and phase minimization, the MATD delivers simultaneous auditive and tactile content..."

From http://science.slashdot.org/comments.pl?sid=15207678&cid=59412448.