Study of the onset of the acoustic streaming in parallel plate resonators with pulse ultrasound

•Study of the onset of the acoustic streaming in pulse and continuous mode.•The particle size and the resonator geometry influence the acoustic streaming.•Pulse mode allow us to manipulate particles smaller than 2 μm.

In a previous study, we introduced pulse mode ultrasound as a new method for reducing and controlling the acoustic streaming in parallel plate resonators (Hoyos and Castro, 2013). Here, by modifying other parameters such as the resonator geometry and the particle size, we have found a threshold for particle manipulation with ultrasonic standing waves in confined resonators without the influence of the acoustic streaming. We demonstrate that pulse mode ultrasound open the possibility of manipulating particles smaller than 1 μm size.