Dr Bruce Drinkwater, from the Department of Mechanical Engineering, University of Bristol, and his colleague Dr Asier Marzo, from Universidad Publica De Navarra in Spain, are the driving force behind the developments. For the first time, acoustic levitation was successfully used to move several particles at once, meaning one day doctors may be able to replicate the procedure inside the human body. The new device features an array of 256 speakers, each around 1cm wide along a distance of 23cm.
Sound exerts a small force and by turning up the volume of ultrasonic waves, scientists create a field strong enough to move objects with precise control.
Dr Marzo and Dr Drinkwater call their invention “Holographic Acoustic Tweezers” (HAT), or simply “acoustic tweezers” in conversation.
It hopes to replace the 2018 Nobel prize winning method known as Holographic Optical Tweezers (HOT), which currently uses lasers.
They published their recent discovery in the Proceedings of the National Academy of Sciences (PNAS) paper on Monday.
Already, the scientists have shown they can connect polystyrene spheres with a thread and use HAT to sew fabric.
Since sound waves travel through tissue, acoustic tweezers may someday deliver drugs to specific organs, clear out kidney stone debris or steer implanted medical devices to new locations inside the body.
Another advantage is that the devices are 100,000 times more power efficient than optical systems.
Dr Drinkwater explained: “Optical tweezers are a fantastic technology, but always dangerously close to killing the cells being moved.
“With acoustics, we’re applying the same sort of forces but with way less energy associated.
“There are lots of applications that require cellular manipulation and acoustic systems are perfect for them.”
The team is confident that the same methodology could be adapted to in-water particle manipulation in approximately one year.
They hope that soon after, it could be adapted for use in biological tissue.
Dr Marzo explained: “The flexibility of ultrasonic sound waves will allow us to operate at micrometre scales to position cells within 3D printed assemblies or living tissue.
“Or on a larger scale, to levitate tangible pixels that form a physical hologram in mid-air.”