Milliseconds mixing in microfluidic channel using focused surface acoustic wave

A feasible approach of acoustic wave based ultra-fast homogeneous mixing in microfluidic channel is reported. After comparing simulation models of energy distribution between parallel interdigital transducers (IDTs) and concentric circular type focused interdigital transducers (F-IDTs), the F-IDTs were designed and built into microfluidic device to generate focused surface acoustic wave in a specific region of the microchannel. In the acoustic enhanced mixing region, continuous laminar flow was mixed efficiently in milliseconds by concentrated acoustic radiation. The active enhanced ultra-fast mixing was optimized and analyzed experimentally. This method could be developed for fast chemical or biochemical reactions and assays. (C) 2011 Elsevier B.V. All rights reserved.