Living Reference Work Entry

Encyclopedia of Microfluidics and Nanofluidics

pp 1-4

Date: Latest Version

Ultrasonic Pumps

  • Barbaros CetinAffiliated withMechanical Engineering Department, Bilkent University Email author 
  • , Reza SalemmilaniAffiliated withMechanical Engineering Department, Bilkent University
  • , Dongqing LiAffiliated withDepartment of Mechanical Engineering, University of Waterloo


Acoustic pumps; Acoustic streaming pumps


Ultrasonic pumps are the pumps that use acoustic streaming effect to create fluid flow. The acoustic streaming effect arises from the interaction between the surface acoustic waves (SAW) traveling inside a piezoelectric substrate and the fluid. Attenuation of the SAW traveling inside the fluid (via reflection, diffraction, etc.) generates a body force within the fluid which is in the direction of wave propagation and converts acoustic energy into kinetic energy of the fluid [1]. SAW devices can be used to transport droplets on a free surface between the input and output piezoelectric transducers (also known as interdigital transducer (IDT)). A schematic drawing of such a device is given in Fig. 1. Moreover, the same mechanism can be used to drive droplets as well as bulk fluid inside closed microchannels.
Fig. 1

Schematic drawing of a typical SAW device used for driving droplets on a free surface


Acoustic pumping has clear ...

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