Sonic tractor beam invented by UltraHaptics can lift and transport small objects

“Our sonic tractor beam technology utilises ultrasound of 40 kHz frequency”, Deepak Sakoo, a researcher at the University of Sussex who was involved in the paper, told IBTimes UK.

We may not have real hoverboards yet, but engineers have just invented a device that can levitate tiny objects using only the power of sound – a sonic tractor beam. One day, it could even be used to suspend and manipulate tiny structures inside the human body, clearing blood clots easily. “If you have a two-dimensional surface that projects different sound waves, you can create any shape from these acoustic fields”. The third type of force field acts a bit like a swirling tornado, with a rotating high-pressure field surrounding a low-pressure, quiet “eye” that holds the object in place, the researchers report today (Oct. 27) in the journal Nature Communications.

Unlike previous attempts to use sound in this way, the object does not need to be surrounded by speakers.

To accomplish this task, the team used a tiny array of 64 mini loudspeakers, made by a company called Ultrahaptics, that produce exquisitely timed sound waves with accuracy to the microsecond level.

By carefully controlling the output of the speakers, the bead can be lifted, held stationary, moved and rotated.

So Drinkwater, his Ph.D. student Asler Marzo and other colleagues ran computer simulations through myriad different patterns of sound waves to find the ones that produced the signature combination of a low-pressure region surrounded by high-pressure zones.

Scientists created acoustic holograms with shapes such as tweezers, twisters and cages that exert forces on particles to levitate and manipulate them.

“The possibility of holding and manipulating objects from a distance and without physical contact is intrinsically exciting”, Marzo stated in an email. Plus, the frequency of the sound waves determines the object that can be lifted.

The high-pitch, high-intensity waves are inaudible to the human ear but combined to control the ball.

This innovation greatly adds to the practical applications of the device – a tractor beam is much more useful if it isn’t stuck inside a box. This is the first time acoustic holograms have been described, according to Marzo, and the first time they’ve been used in this context.

We’re still years away from being able to apply sound levitation to medicine, Marzo says.

They could also grip and transport drug capsules to help navigate them to the right location or manipulate microsurgical instruments through living tissue.