Using Sound Waves, Scientists Create Acoustic Tweezers To Sew A Thread Into Fabric

For the very first time, sound waves have been successfully used for manipulating and levitating objects by scientists, who first implemented them in sewing a thread into a piece of cloth.

The scientists are researching other implementations of the system such as stitching up closed-head injuries or carrying medicine to specific places in human’s internal organs.

Sound creates a small but effective acoustic force, and scientists raise the ultrasonic wave volume to such high pitch that humans cannot hear. This helps them generate a sound field so strong that it can move small objects.

Scientists from Universidad Publica De Navarra in Spain and Bristol University in the UK performed an experiment involving attaching two millimetric polystyrene spheres into a thread and using the sound system as tweezers to sew it to a piece of cloth. Moreover, the system could perform the act on 25 of those spheres simultaneously in the air.

As stated by Professor Bruce Drinkwater, the system grants them more versatility – with multiple couples of hands to carry out things and complete complex actions, which creates a pathway to new possibilities that weren’t there before.

An intricate, tweezer-like, acoustic field can be created using a novel algorithm that adjusts an array of 256 small loudspeakers, according to Asier Marzo, Universidad Publica De Navarra.

Acoustic tweezers levitate small objects

Similar to optical tweezers, which was the winner of the 2018 Nobel prize, acoustic tweezers also use lasers to capture and move micro-particles, but the acoustic tweezer has the upper-hand in working inside human tissues.

Ultrasound has been frequently used in kidney stone treatments and pregnancy scans for it has no effects on biological tissue, unlike lasers, which are very tricky to use upon biological tissue as they can only travel through a transparent medium.

Another benefit is that acoustic systems generate power 100,000 more efficiently compared with optical systems.

As further stated by professor Drinkwater, the acoustic system provides the same kind of force as the optical system, with less hazard and energy-consumption. Also, there are many applications related to cellular manipulation that suit perfectly with the acoustic system.

The research team is positive that the system can also be applied for particles in water in the next one year. They also look forward to performing the system on biological tissue.

The versatility of ultrasound waves will enable the scientists to operate in not only a micrometer scales to place cells within living tissue or 3D printed assembles but also on a larger scale to form a physical hologram by levitating tangible pixels in mid-air – stated by Professor Drinkwater.