Sound Waves Can Lift Small Items With Help of Acoustic Tweezers

Aug, 2021 - By WMR

Researchers have breached uncharted territory with the use of sound waves to collect an object from a hard reflective area.

It may seem flashy, but there have been several unique ways in which researchers have seen the concept of using ultrasound wave to levitate small objects. Researchers in Japan have now introduced a new one to the category, which could offer this experimental technology more into functional use by first showing how small polystyrene balls can be lifted off a rigid surface. In previous years, researchers have experimented with different kinds of ‘sound tweezers’ system using cautiously targeted sound waves to float water drops, laboratory made cartilages and also to lift significantly lager items by using ‘acoustic tractor beams’.

All work by sending sound waves down to the curved reflector by using a transducer, which rebounces them upwards and leads them to meet in the middle to create a new type of wave with enough pressure to support small objects. Researchers at the University of Tokyo Metropolitan attempted to step out of the comfort zone by creating an acoustic tweezer mechanism that would pick up an object from sounding stage, a wooden board to be more specific. In this respect, a new hemispheric range of transducers has to be developed and the technical obstacles related with the precise management of multiple sound waves in real time have to be overcame, so as to allow small items to be levitated over the platform. The group separated its hemispheric range of transductors in eight blocks in order to address this complex issue and overturned the polarity of half of each block.

Individually optimized phase and amplitude of the sound waves emanating from each block, the system can create an acoustic trap in an extremely particular position, which can be changed by altering the behavior. This was explained through a sequence of experiments, followed by experimental tests in which the array was used to elevate and levitate a polystyrene ball 3mm in diameter above a plank of wood. The method was not at all ideal, with the ball not always elevating and sometimes tossing, but the researchers aim to continue improving as they operate toward practical application or the innovation.