Patterning microparticles into a two-dimensional pattern using one column standing surface acoustic waves

The patterning of micro particles in microfluidic networks is important for many biological and medical applications. In this paper, the micro particles patterns that driven by standing surface acoustic wave (SSAW) are investigated in microchannel. A two-dimensional particle pattern is formed by the micro particles under the actuation of one column SSAW. Two forces, i.e., chaining force generated by interaction of polarized particles, and acoustic radiated force (ARF) generated by the surface acoustic wave (SAW), should dominate the particles assembling process. The intricate and interesting interplay between acoustic radiation force and chaining force on the particles is studied. The analysis and experiment reveal that the ARF drives the particles to form broken line along the nodal line (one-dimensional particle pattern) where the ARF is zero and the chaining force can dominate the particles to form array points (two-dimensional particle pattern) in the area of node. The results will be useful for deeply understanding the particles moving and precisely control the particles patterns induced by SSAW. (C) 2018 Elsevier B.V. All rights reserved.