How many times have you wished that at the end of the day, some magic hand would pick up the things scattered messily all over the chairs and tables? That magic hand, or its ultrasonic equivalent, has been effectively designed now. A team of researchers, Asier Marzo et al, from Universities of Bristol, Sussex and Navarre and Ultrahaptics Limited have come up with a way to use sound to “pick up” objects. In a study published recently in Nature Communications, the team has demonstrated using 64 miniature speakers how high-pitch and high-intensity ultrasonic sound waves can be used to surround a small object and create a force field which can then “hold” the object. By manipulating the output of the loudspeakers the object can then be moved.
This is interesting because it differs from earlier attempts which required that the object that was to be lifted be surrounded by loudspeakers in all directions. Dr. Marzo and his team achieved it using a plane array of loudspeakers. The invisible hand that they created was of three types — tweezers, twisters and bottles. The tweezers were similar to lifting the object with a pair of fingers, while the twisters surrounded the object in a vortex of sound, and finally, the bottles were like a cage that trapped the object within.
In a video released by the group, the scientist brings in a small ball, a few millimeters across, to a point above the array of loudspeakers. He then draws away the paper. As if a pair of fingers is holding it back, the ball is seized and held in place as the paper is pulled away. While at the moment they are able to manipulate objects of width about 2 mm only, the scientists hope to perfect the technique to be able to manipulate small, cell-sized objects and also much larger ones.
