Sound waves can make these particles dance in the air | Science News

Unlike other devices that could levitate only one object or move around particles as a group, a new device (left) uses ultrasonic waves to independently steer up to 25 millimeter-sized particles in different directions simultaneously (shown here manipulating six foam balls). The device (shown in a computer simulation on the right) uses two grids of ultrasonic speakers (rainbow-colored dots at top and bottom) to create sound fields between the speaker arrays. In these sound fields, particles get trapped in r