Acoustic tweezing for patterning and discriminating particles

We present a novel sensor device that acoustically patterns and discriminates micron-scale particles. Such techniques, that allow the micro-manipulation and isolate cells, particles or droplets by non-invasive means, are desired to facilitate biophysical or biological applications such as microarrays and tissue engineering. Here, our approach utilizing a static acoustic field to pattern particles and a dynamic acoustic field that is capable of separating an arbitrary size range of particles. We first demonstrate the method for the separation of particles with different diameters between 6 and 45 μm. The shearless, label free and low damage characteristics make this method of manipulation particularly suited for biological applications. Advantages of using a dynamic acoustic field for the separation of particles include its tunability and adapt to the entities that need to be separated, inherent safety and biocompatibility, the possibility to operate over large distances (centimetres), high purity (ratio of particle population, up to 100%), and high efficiency (ratio of separated particles over total number of particles to separate, up to 100%).