Lateral Movement of Particles in a Levitating Acoustic Field

Acoustic levitation is an interesting technique used for levitating small objects/materials using sound waves. In this study, lateral movement of levitating particles is demonstrated experimentally and numerically. The method can simultaneously move multiple particles and the paper demonstrates levitation for three particles. Initially, an ultrasonic tweezer with a resonance frequency of 40 kHz is used to levitate three particles of average weight of 0.15 mg each. The experimental design is based on numerical simulation. Further, the levitated particles are moved in a lateral direction using two ultrasonic tweezers setup by manipulating the phase of one of the tweezers using Arduino Nano. As evident by simulations, the movement takes place due to the interference of waves leading to the movement of pressure node. The lateral movement of particles can be controlled and even reversed by changing the phase difference.