Three Japanese researchers, Yoichi Ochiai, Takayuki Hoshi, and Jun Rekimoto, have managed to create an ultrasonic array that can push items around in 3D space. The system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays.