We report a microfluidic fluorescence activated cell-sorting (μFACS) device that employs traveling surface acoustic waves (TSAW) to sort cells at rates comparable to conventional jet-in-air FACS machines, with high purity and viability.

We demonstrate an acoustic wave driven microfluidic cell sorter that combines advantages of multilayer device fabrication with planar surface acoustic wave excitation. We harness the strong vertical component of the refracted acoustic wave to enhance cell actuation by using an asymmetric flow field to increase cell deflection. Precise control of the 3-dimensional flow is realized by topographical structures implemented on the top of the microchannel. We experimentally quantify the effect of the structure dimensions and acoustic parameter. The design attains cell sorting rates and purities approaching those of state of the art fluorescence-activated cell sorters with all the advantages of microfluidic cell sorting.

We generate traveling surface acoustic waves with an interdigital transducer to create droplets on-demand; encapsulate single cells; lyse cells and immediately encapsulate their contents; and pico-inject new materials into existing droplets.

We introduce a microfluidic device that uses traveling surface acoustic waves to lyse bacteria with high efficiency. This lysis method should be applicable to a wide range of bacteria species and can be modified to analyze individual bacteria cells.