his video shows the movement of a deionized water drop provoked by surface acoustic waves. The waves are generated by means of an interdigited transducer laid on a piezoelectric substrate. Surface waves are launched when an alternating voltage at the resonance frequency of the transducers is applied. The waves propagating on the substrate surface reach the liquid/substrate interface and radiate a longitudinal wave into the liquid droplet. The latter causes a streaming movement within the drop. When SAW driving force reaches a certain critical value (depending on several parameters, such as the drop’s size and shape or the power input at the transducer), the force generated by the streaming enables the displacement of the drop in the direction of wave propagation.