Sussex University researchers have developed the world’s first ultrasound levitation technology.
Called SoundBender, the technology is an interface capable of producing dynamic self-bending beams that enable both levitation of small objects and tactile feedback around an obstacle.
The breakthrough was carried out by Professor Sriram Subramanian, Dr Gianluca Memoli and Dr Diego Martinez Plasencia.
SoundBender overcomes two key limitations of previous ultrasound levitation set-ups namely, 1) their inability to create sound fields of similar complexity, 2) and bypassing obstacles that lay between the transducers and the levitating object.
“This is a significant step forward for ultrasound levitation and overcomes a significant drawback that has been hampering development in this field. We have achieved incredibly dynamic and responsive control, so real-time adjustments are just one step away,” said Dr Memoli.
The researchers developed a hybrid system that combines the versatility of Phased Arrays of Transducers (PATs) with the precision of acoustic metamaterials while helping to eliminate the restrictions on sound field resolution and variability each of the previous approaches applied.
The technology allows users to experience haptic feedback beyond an obstacle; to levitate around an obstacle and to manipulate non-solid objects such as changing the direction of a candle’s flame.
With SoundBender, the metamaterial provides a low modulator pitch to help create sound fields with high spatial resolution while the PAT adds dynamic amplitude and phase control of the field.
The development opens up new potential in ultrasound levitation, which has a distinct advantage over other levitation techniques because it requires no specific physical properties, such as magnetic or electric, in the object to be levitated and can therefore be applied to a far wider range of materials including liquids and food.
According to the researchers, the concept of self-bending beams was initially used in engineering applications, to obscure buildings from noise or protect areas from earthquakes.
This is the first time it’s been adopted for use in acoustic levitation.
University of Sussex