Acoustic levitation for multimodal volumetric display

Current display approaches, such as VR, allow us to get a glimpse of multimodal 3D experiences, but users need to wear headsets as well as other devices in order to trick our brains into believing that the content we are seeing, hearing or feeling is real. Light-field, holographic or volumetric displays avoid the use of headsets, but they constraint the user’s ability to interact with them (e.g. content is not reachable to user’s hands, user’s constrained to specific locations) and, most importantly, still cannot simultaneously deliver sound and touch. In this talk, we will present the Multimodal Acoustic Trapping Display (MATD): a mid-air volumetric display that can simultaneously deliver visual, tactile and audio content, using phased arrays of ultrasound transducers. The MATD makes use of ultrasound to trap, quickly move and colour a small particle in mid-air, to create coloured volumetric shapes visible to our naked eyes. Making use of the pressure delivered by the ultrasound waves, the MATD can also create points of high pressure that our bare hands can feel and induce air vibrations that create audible sound. The system demonstrates particle speeds of up to 8.75 m/s and 3.75 m/s in the vertical and horizontal directions, respectively. In addition, our technique offers opportunities for non-contact, highspeed manipulation of matter, with applications in computational fabrication and biomedicine.