Microfluidic acoustophoresis is a label-free technique that isolates a purified product from a complex mixture of cells. This technique is well-studied but thus far has lacked the throughput and device manufacturability needed for many medical and industrial uses. Scale-up of acoustofluidic devices can be more challenging than in other microfluidic systems because the channel walls are integral to the resonant behavior and coupling to neighboring channels can inhibit performance. Additionally, the increased device area needed for parallel channels becomes less practical in the silicon or glass materials usually used for acoustofluidic devices. Here, we report an acoustic separator with 12 parallel channels made entirely from polystyrene that achieves blood cell separation at a flow rate greater than 1 ml/min. We discuss the design and optimization of the device and the electrical drive parameters and compare the separation performance using channels of two different designs. To demonstrate the utility of the device, we test its ability to purify lymphocytes from apheresis product, a process that is critical to new immunotherapies used to treat blood cancers. We process a leukapheresis sample with a volume greater than 100 ml in less than 2 h in a single pass without interruption, achieving greater than 90% purity of lymphocytes, without any prepurification steps. These advances suggest that acoustophoresis could in the future aid in cell therapy bioprocessing and that further scale-up is possible.

Microplastics (MPs) have been found in aqueous environments ranging from rural ponds and lakes to the deep ocean. Despite the ubiquity of MPs, our ability to characterize MPs in the environment is limited by the lack of technologies for rapidly and accurately identifying and quantifying MPs. Although standards exist for MP sample collection and preparation, methods of MP analysis vary considerably and produce data with a broad range of data content and quality. The need for extensive analysis-specific sample preparation in current technology approaches has hindered the emergence of a single technique which can operate on aqueous samples in the field, rather than on dried laboratory preparations. In this perspective, we consider MP measurement technologies with a focus on both their eventual field-deployability and their respective data products (e.g., MP particle count, size, and/or polymer type). We present preliminary demonstrations of several prospective MP measurement techniques, with an eye towards developing a solution or solutions that can transition from the laboratory to the field. Specifically, experimental results are presented from multiple prototype systems that measure various physical properties of MPs: pyrolysis-differential mobility spectroscopy, short-wave infrared imaging, aqueous Nile Red labeling and counting, acoustophoresis, ultrasound, impedance spectroscopy, and dielectrophoresis.