A team of researchers at the University of Sussex have created a multimodal acoustic trap display (MATD) that creates 3D floating and animated images that can produce sound, visual and tactile (touch) content, similar to sci-fi holograms.
The system traps a particle acoustically and illuminates it with RGB light to control its colour, scanning the display volume and using time multiplexing with a secondary trap to deliver simultaneous audio and tactile content that users can engage with.
The system demonstrates particle speeds of up to 8.75m per second and 3.75m per second in vertical and horizontal directions.
The MATD creates visual content by levitating a 1mm radius, white, expanded polystyrene particle as an approximation to a Lambertian surface, using predictive models of acoustic trapping forces, with the twin trap model.
Dr Ryuji Hirayama, JSPS scholar and Rutherford Fellow at the University of Sussex was the lead author of the project. Hirayama explained: “Our new technology takes inspiration from old TVs which use a single colour beam scanning along the screen so quickly that your brain registers it as a single image. Our prototype does the same using a coloured particle that can move so quickly anywhere in 3D space that the naked eye sees a volumetric image in mid-air.”