PROJECT ABSTRACT This focused technology research and development project will deliver a new class of acoustic separation/en- richment tools for multiple biomedical research applications. Acoustic microfluidics has emerged as a key ena- bling technology in biology and medicine, providing unmatched capability for non-contact, label-free object ma- nipulation and analysis. The proposed microfluidic platform is based on a novel concept: a longitudinal standing bulk acoustic wave (LSBAW) subunit that controls micro- to nanoscale objects for functional separation and/or confinement. The patented LSBAW subunits are highly configurable, which allows arrays of repeated subunits to meet varying capacity and throughput needs, from monitoring/detection in small-volume (sub-µL) reaction chambers to high-throughput enrichment of rare species. Outcomes of this project will include purpose-built prototype systems for: (i) high-throughput enrichment/fractionation, (ii) process control at high capacity, and (iii) multiplexed analyses with real-time monitoring. To establish the versatility and utility of the LSBAW platform, different configurations will be validated in research applications of value to, for example, cancer biologists (rare cell enrichment), synthetic biochemists (antibody conjugate synthesis on ultrasound-confined reaction sub- strates), and microbiologists (monitoring/measurement of biological mechanisms in bacterial cells). The technol- ogy outcomes of this project will be relevant not only to those applications, but will be broadly applicable to any field that relies on separation, isolation, and enrichment. The project includes three Aims: Aim 1: Demonstrate scalability of LSBAW subunits for high-volume, high-throughput enrichment of rare species. Aim 2: Validate series configurations of LSBAW subunit arrays for high-capacity cell modification/labeling or custom biomolecule synthesis. Aim 3: Validate multiplexed configurations of LSBAW subunit arrays for quantification and/or detection of a target species or biological mechanism. Validation experiments will be used to rigorously assess capabilities that are relevant to specific applications. Use of standard models (e.g., microparticles as proxies for biological cells) or well-characterized biological sys- tems (e.g., commercial antibodies; standard mammalian cell lines, mixtures of cells, and microbes) will ensure consistency and reproducibility of results. In each application, success will be defined using quantitative perfor- mance criteria (e.g., throughput, capacity, specificity, sensitivity) and comparison with appropriate existing tools and methods. The team merges expertise in microfluidics, synthesis and characterization of imaging agents, microbiology, and rare cell isolation/analysis, with strong track records of technology development and deploy- ment. Completion of these aims will translate a novel acoustic microfluidics concept to a suite of powerful and broadly accessible research tools that will accelerate research in a multitude of biomedical research fields.

PROJECT NARRATIVE Efficient separation, isolation, and enrichment of specific molecules and cells are critical research steps in biol- ogy, biotechnology, and medicine, with each playing an important role in advancing biomedical research. Micro- fluidic devices offer promising solutions that can achieve these steps with precise control, but these technologies are currently limited to small amounts of sample, restricting the amount or rate of processing. In the proposed project, these obstacles are overcome by a new technology platform, based on highly configurable arrays of microfabricated features, that uses sound to move and trap small particles and cells for a wide variety of research applications involving enrichment, isolation, and separation.