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

健康和福祉、可持续能源以及环境评估和保护是当今社会面临的最重要挑战之一，突显了对先进材料研究的迫切需要。在过去的二十年里，全球对将导致具有新功能的新型纳米材料的研究投资大幅增加，以满足这一需求。然而，由于操作的不确定性、低吞吐量和调节纳米材料性能的能力有限，目前使用的大多数间歇规模的系统仍然存在大的尺寸分布和批次之间的差异。许多研究表明，通过健壮的单(生物)粒子分析(SPA)可以取得突破，这需要获得超小的、可单独寻址的反应囊泡。液滴微流体(DM)具有满足这一关键需求的巨大潜力，因为在微流体通道网络中，通过将一种流体(即水)注入另一种不互溶的流体(即油)，可以以KHz的速率产生大小从皮升(PL)到纳升(NL)的单分散液滴，从而解决了低吞吐量问题。这些超小液滴具有良好的表面特性，可完全被载液包裹，最大限度地减少交叉污染。这些特点使DM成为SPA的理想系统，因此是强大的纳米材料合成系统。 在这项广泛的翻译研究计划中，我们将调查DM作为SPA使能系统的基本限制，然后开发集成了强大的、自动化的主动操纵、传感和加热单个液滴的调制系统，为SPA提供单独可寻址的反应囊，用于纳米材料的合成和制造。具体地说，我们将开发一种新的策略，利用计算机视觉反馈来驱动施加到流体上的压力，以坚固、自动化的方式操纵单个液滴，而不会使系统硬件进一步复杂化。我们还将研究单个液滴的微波传感和加热的基本原理及其多路复用能力，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，然后通过开发能够即插即用操作的阀门将这些功能集成到调制系统中，以将其应用推广到各种领域，如纳米材料的合成和制造、药物筛选、生命科学研究以及环境评估和保护。

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.