Acoustofluidic Droplet Sorter Based on Single Phase Focused Transducers

Droplet microfluidics has revolutionized the biomedical and drug development fields by allowing for independent microenvironments to conduct drug screening at the single cell level. However, current microfluidic sorting devices suffer from drawbacks such as high voltage requirements (e.g., >200 Vpp), low biocompatibility, and/or low throughput. In this article, a single‐phase focused transducer (SPFT)‐based acoustofluidic chip is introduced, which outperforms many microfluidic droplet sorting devices through high energy transmission efficiency, high accuracy, and high biocompatibility. The SPFT‐based sorter can be driven with an input power lower than 20 Vpp and maintain a postsorting cell viability of 93.5%. The SPFT sorter can achieve a throughput over 1000 events per second and a sorting purity up to 99.2%. The SPFT sorter is utilized here for the screening of doxorubicin cytotoxicity on cancer and noncancer cells, proving its drug screening capability. Overall, the SPFT droplet sorting device shows great potential for fast, precise, and biocompatible drug screening. Single phase focused transducer (SPFT) is a novel acoustofluidic tool for droplet sorting, using a unique interdigital transducer design. The capability of the SPFT to generate high acoustic intensities enables high efficiency cell‐laden droplet sorting with a low input voltage and a high biocompatibility. This new sorting technology shows significant potential as a tool for droplet‐based screening and analysis.