Precise and programmable manipulation of microbubbles by two-dimensional standing surface acoustic waves

A microfluidic device is developed to transport microbubbles (MBs) along a desired trajectory in fluid by introducing the phase-shift to a planar standing surface acoustic wave (SSAW). The radiation force of SSAW due to the acoustic pressure gradient modulated by a phase-shift can move MBs to anticipated potential wells in a programmable manner. The resolution of the transportation is approximately 2.2 mu m and the estimated radiation force on the MBs is on the order of 10(-9) N. This device can be used for manipulation of bioparticles, cell sorting, tissue engineering, and other biomedical applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704922]