Research Program on Developing Modulated Droplet Microfluidic Systems Towards Robust Nanomaterial Synthesis

健康和福祉，可持续能源，环境评估和保护是当今社会面临的最重要的挑战之一，强调了对先进材料研究的迫切需要。在过去的二十年中，为了满足这一需求，全球对具有新功能的新型纳米材料的研究投资急剧增加。然而，由于操作的不确定性、低通量和有限的调整纳米材料性质的能力，目前大多数使用的批量系统仍然存在大尺寸分布和批次之间的差异。许多研究表明，通过强大的单（生物）颗粒分析（SPA）可以取得突破，这需要超小型、可单独寻址的反应囊泡的可用性。微液滴微流体（DM）在满足这一关键需求方面具有巨大的潜力，因为在微流体通道网络中，通过将一种流体（如水）注入另一种不混相的流体（油）中，可以以kHz速率产生单分散的液滴，尺寸从皮升（pL）到纳升（nL），从而解决了低通量问题。由于具有良好的表面控制特性，这些超小型液滴完全被载液包裹，最大限度地减少了交叉污染。这些特点使DM成为SPA的理想系统，因此具有强大的纳米材料合成能力。

Health and well-being, sustainable energy, and environmental assessment and protection are among the most important challenges facing today's society, underscoring the urgent need for advanced materials research. In the past two decades, global investment in research that will lead to novel nanomaterials with new functionalities has increased dramatically to meet this need. However, most currently used batch-scale systems still suffer from large size distribution and batch-to-batch variations due to operational uncertainties, low throughput and limited capability for tuning the properties of nanomaterials. Many studies have suggested breakthroughs can be made via robust single (bio)particle analysis (SPA), which calls for the availability of ultra-small, individually addressable reaction vesicles. Droplet microfluidics (DM) holds tremendous potential to meet this critical need because monodispersed droplets, picoliter (pL) to nanoliter (nL) in size, can be generated at kHz rates in microfluidic channel networks by injecting one fluid (i.e. water) into another immiscible one (oil) which addresses the low throughput issue. With well controlled surface properties, these ultra-small droplets are fully encapsulated by the carrier fluid minimizing cross contamination. These features make DM an ideal system for SPA and thus robust nanomaterial synthesis. In this broad translational research program, we will investigate the fundamental limitations of DM as an enabling system for SPA and then develop modulated systems integrated with robust, automated active manipulation, sensing and heating of individual droplets to provide individually addressable reaction vesicles for SPA towards nanomaterial synthesis and manufacturing. Specifically, we will develop a novel strategy that utilizes computer vision feedback to actuate the pressures applied to the fluid to manipulate individual droplets in a robust, automated manner without further complicating the system hardware. We will also investigate the fundamentals of microwave sensing and heating of individual droplets and their multiplexing capacity, meaning the integration of multiple sensors and heaters on a typical microfluidic device footprint, and then integrate these functions into modulated systems by developing valves enabling plug-and-play operation to generalize their applications to a wide variety of areas such as synthesis and manufacturing of nanomaterials, drug screening, life science research and environmental assessment and protection.