Collaborative Research: Liquid Phase Atomic Layer Deposition of Thin Films on Nanoparticles Using Three-Dimensionally Printed Microfluidics

纳米颗粒是尺寸在1至100纳米之间的颗粒，由于其高表面积与体积比，其具有独特的尺寸依赖性。功能性纳米颗粒具有通过诸如药物递送、磁共振成像、可再生能源、光电子学和催化等应用造福社会的潜力。 这些应用依赖于使用薄膜涂层精确定制纳米颗粒表面化学的能力。 纳米颗粒薄膜涂层的厚度通常为几个单层的数量级，但必须均匀地施加到各个纳米颗粒上。该奖项支持对一种新的高精度薄膜纳米颗粒涂层策略的基础研究，该策略通过结合原子层沉积，三维打印和微流体的原理，克服了当前的制造挑战，包括涂层不均匀性。 提高纳米颗粒涂层的均匀性使功能性纳米颗粒能够在健康，能源和技术领域中获得新的应用。 该研究奖通过纳米粒子应用的实践教育演示支持公众参与纳米技术，重点是促进历史上在制造业研究中代表性不足的群体，如妇女和少数民族的包容性。纳米颗粒的薄膜涂层的当前挑战包括颗粒聚集、不均匀的涂层、有限的厚度控制以及对颗粒尺寸和形态的不期望的敏感性。 该研究奖通过将传统原子层沉积的单层单层沉积原理与称为确定性横向位移的流体动力学纳米粒子操作方法相结合来满足这些挑战，以实现称为“液相原子层沉积”的新纳米制造技术。 这种方法代表了从基于在固-气界面处沉积的常规原子层沉积到基于在固-液界面处的连续吸附和沉积反应的新的沉积物理学的转变。 该研究的中心是利用微流体通道内特殊定位的纳米柱，将悬浮的纳米颗粒被动地输送到连续反应物和洗涤溶液的离散相邻流动流中。 据推测，液相原子层沉积的受控固-液界面现象产生纳米颗粒薄膜涂层的高度精度和均匀性。通过基于双光子直接激光写入的增材制造构建的并行三维微流体反应器的工程设计确保了该方法也具有高通量。 该研究团队通过基础实验研究、计算流体动力学模拟和多物理场有限元建模来研究液相原子层沉积现象。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nanoparticles are particles between 1 and 100 nanometer in size that possess unique, size-dependent properties due to their high surface area-to-volume ratios. Functional nanoparticles have the potential to benefit society through applications such as drug delivery, magnetic resonance imaging, renewable energy, optoelectronics, and catalysis. These applications rely on an ability to precisely customize the surface chemistry of nanoparticles using thin-film coatings. Nanoparticle thin-film coatings are typically on the order of a few monolayers in thickness, yet must be uniformly applied to individual nanoparticles. This award supports fundamental research into a new, high-precision thin-film nanoparticle coating strategy that overcomes current manufacturing challenges, including coating non-uniformity, by combining principles of atomic layer deposition, three-dimensional printing, and microfluidics. Improving the uniformity of nanoparticle coatings enables new applications of functional nanoparticles across health, energy, and technology sectors. This research award supports public engagement with nanotechnology through hands-on educational demonstrations of nanoparticle applications, with a focus on promoting inclusion for groups historically underrepresented in manufacturing research such as women and minorities. Current challenges in thin-film coating of nanoparticles include particle aggregation, non-uniform coating, limited thickness control, and undesired sensitivity to particle size and morphology. This research award meets these challenges by combining the monolayer-by-monolayer deposition principle of conventional atomic layer deposition with the hydrodynamic nanoparticle manipulation approach known as deterministic lateral displacement to achieve a new nanomanufacturing technology termed 'Liquid Phase Atomic Layer Deposition'. This approach represents a shift from conventional atomic layer deposition based on deposition at the solid-vapor interface to a new deposition physics based on successive adsorption and deposition reactions at the solid-liquid interface. The research studies center on utilizing specially positioned nanoposts within a microfluidic channel to passively transport suspended nanoparticles into discrete, adjacent flow streams of successive reactant and wash solutions. It is hypothesized that the controlled solid-liquid interface phenomena of Liquid Phase Atomic Layer Deposition yields a high degree of precision and uniformity for nanoparticle thin-film coating. The engineering of parallel three-dimensional microfluidic reactors, constructed by means of two-photon direct laser writing-based additive manufacturing, ensures that this method is also high throughput. The research team investigates the phenomenon of Liquid Phase Atomic Layer Deposition through fundamental experimental studies, computational fluid dynamics simulations, and multiphysics finite element modeling.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.