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挑战之一，这凸显了对先进材料研究的迫切需求。在过去的二十年里，为满足这一需求，全球对研究具有新功能的新型纳米材料的投资急剧增加。然而，由于操作的不确定性、低通量和调节纳米材料性质的能力有限，目前大多数使用的批量规模系统仍然存在大尺寸分布和批次间变化。许多研究表明，通过强大的单（生物）粒子分析（SPA）可以取得突破，这需要超小的，可单独寻址的反应囊泡的可用性。液滴微流体（DM）具有满足这一关键需求的巨大潜力，因为通过将一种流体（即水）注入另一种不混溶的流体（油）中，可以在微流体通道网络中以kHz速率产生尺寸为皮升（pL）至纳升（nL）的单分散液滴，这解决了低通量问题。这些超小液滴具有良好的表面特性，可被载液完全包裹，最大限度地减少交叉污染。这些特性使DM成为SPA的理想系统，从而使其成为强大的纳米材料合成。 在这个广泛的转化研究计划中，我们将研究DM作为SPA使能系统的基本限制，然后开发集成了强大的自动化主动操作，传感和加热单个液滴的调制系统，为SPA提供可单独寻址的反应囊泡，以实现纳米材料的合成和制造。具体来说，我们将开发一种新的策略，该策略利用计算机视觉反馈来驱动施加到流体上的压力，从而以鲁棒的自动化方式操纵单个液滴，而不会使系统硬件进一步复杂化。我们还将研究微波传感和加热单个液滴及其多路复用能力的基本原理，这意味着在典型的微流体设备足迹上集成多个传感器和加热器，然后通过开发阀将这些功能集成到调制系统中，使即插即用操作将其应用推广到各种各样的领域，如纳米材料的合成和制造，药物筛选，生命科学研究和环境评价与保护。

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.