Using a grid of loud speakers tuned to an ultrasound frequency scientists levitate multiple objects in mid-air. By adjusting the angle and power of each speaker they can form different shapes, such as a pyramid or cube. Eventually they were even able to perform a delicate sewing maneuver.
Ultrasound is a frequency so high we cannot even hear it. Several months ago researchers figured out how to levitate objects around a corner, now, using similar techniques they have begun levitating multiple objects by tuning a grid of speakers to “push” against each other, and trap objects in the neutral zone between acoustic waves.
Earlier this year, the same team built a “sonic tractor beam” that levitated a 16-millimeter-wide Styrofoam ball. Now, using two grids composed of 256 speakers combined with a proprietary computer algorithm they have successfully manipulated up to 25 polystyrene balls simultaneously. The balls are between 1 and 3 millimeters wide, roughly the same size of a small ant.
To top it all off the team of researchers ran a piece of thread between two of the polystyrene balls and successfully performed a basic sewing maneuver that threaded the string through a hole in a levitating piece of fabric.
Scientists claim the new experiment has practical implications beyond sewing. Through the use of ultrasound to manipulate delicate biological samples you could avoid risk of contamination or wear that would otherwise come with handling the object. They also claim that it would be possible to manipulate surgical tools, drugs and kidney stones WITHIN the human body using these ultrasound frequencies.
Furthermore, acoustic levitation has previously been proposed as a means of detecting contaminated water – by levitating droplets until heavier metallic compounds sink to the bottom.