The idea has been floated previously to use sound waves to make objects levitate. Research confirmed it, but as you may expect, this requires a direct path of waves to the object – interrupt them by placing something in the way, and things go downhill fast. Now, scientists have found a way to keep the objects floating even when the path is interrupted by other objects, marking a huge advance in our sci-fi dreams of levitation.  

Even better, you can watch it all in a video created by the researchers.    

Their results were published in the journal Science Advances.    

Using 3D levitation, scientists can create incredible displays that can be touched and experienced without an augmented reality headset, but the issue of interference needs to be addressed before that can become possible. A physical object's interference can interrupt the intricate field of acoustic waves needed to make an object float, and this would likely not mix well with the public viewing the display.  

As such, these ultrasound levitation displays currently need to exist in extremely controlled spaces, far away from potential disruptors.  

In an attempt to make levitation displays possible for public spaces like arcades and malls, researchers from University College London developed a system of multiple speakers that could adjust which are turned on or off to account for fluctuations in the levitation field, self-correcting the floating object should anything get in the way.    

“Until now, we’ve only been able to demonstrate acoustic levitation for virtual reality and holograms in controlled environments without any other objects nearby that could interrupt and scatter soundwaves. In this paper, we’ve shown how we can float objects and even create digital content such as holograms in real-world environments by accounting for nearby objects in real-time,” said lead author Dr Ryuji Hirayama in a statement. 

“It opens up the possibilities for fully immersive virtual reality experiences and interactive holograms.”   

The research may not just have implications for making pretty displays, though. Levitating objects accurately could be a huge step in 3D printing and manufacturing, with a floated object able to be acted on from all sides. This way, cross-contamination of materials can be prevented and accurate applications of printing material can be applied.    

“I am excited for how this work opens the door for mixing many different materials in additive manufacturing and 3D printing. Acoustic levitation has huge potential in precision manufacturing and this work paves the way for realising this opportunity,” said lead researcher Sri Subramanian.