SGER: Shape-Dependent, Selective Self-Assembly for Nanomanufacturing

该项目将提供一个初步的演示和表征技术，以快速、有效、廉价地制造复杂的纳米组件系统，以满足未来广泛的纳米制造需求。该技术利用流体的几何选择性自组装，将纳米级组件精确地组织成任意的、预先确定的、非周期的系统。该技术将使集成纳米系统的创建成为可能，从10纳米到大于1毫米的尺寸范围内，单独制造功能纳米组件。对基板进行图案化，使其在给定位置的地形与该位置所需组件的形状完全相反。衬底和组件都用疏水自组装单层（SAM）的毡状涂层进行化学功能化，以促进组件与衬底的附着。所述组件和基材浸入适当的流体中；然后元件随机接触基板并粘附。由于元件-衬底结合能随接触面积的增大而增大，元件在形状匹配的孔中比在非形状匹配的表面上附着得更强。超声速激发选择性地去除不正确放置的、结合较弱的组分，同时保留正确放置的、结合较强的组分。随机接触和选择性去除同时发生，并且组装的构型接近所需的构型。这种方法的优点包括高定位精度，同时和选择性地组装不同的纳米结构，以及一种避免层对层校准步骤的方法。该项目有三个主要目标。首先是表征装配良率和缺陷密度与装配时间、超声速激发强度、疏水性和颗粒/孔匹配质量之间的关系，使用1毫米尺度的颗粒。第二是演示可重复的自组装到平版印刷定义的形状匹配的结合位点。第三是将测量的组装产量与结合能的差异联系起来，以便确定选择性和组件尺寸的限制。创建快速、有效、广泛应用的纳米制造技术（如本文所描述的）是很重要的。关于纳米元件的现有研究有很多，但是将这些纳米元件整合到更大的系统中，将需要更多的研究来将它们转化为实用的系统和新产品。这样的系统可以从单个电子传感器到物理、化学和生物传感器。

This project will provide an initial demonstration and characterization of techniques to manufacture complex systems of nanocomponents rapidly, effectively, and inexpensively to meet a wide array of future nanomanufacturing needs. The proposed technique uses geometrically-selective self-assembly from fluid to organize nanoscale components precisely into arbitrary, pre-determined, non-periodic systems. The technology will enable the creation of integrated nanosystems from separately fabricated functional nanocomponents in the 10 nm to greater than 1 mm size range. The substrate is patterned so that its topography at a given location is the exact inverse of the shape of the desired component at that location. Both substrate and components are chemically functionalized with a blanket coating of a hydrophobic self-assembled monolayer (SAM) to promote component-substrate attachment. The components and substrate are immersed in an appropriate fluid; components then contact the substrate randomly and stick. Because component-substrate binding energy scales with contact area, components attach much more strongly in shape-matched holes than on non-shape-matched surfaces. Megasonic excitation selectively dislodges the incorrectly-placed, more weakly-bound components while retaining the correctly placed, more strongly-bound components. Random contact and selective removal occur simultaneously, and the assembled configuration approaches the desired configuration. The benefits of this approach include high positioning precision, simultaneous and selective assembly of diverse nanostructures, and a means of avoiding layer-to-layer alignment steps. The project has three primary goals. First is to characterize assembly yield and defect density vs. assembly time, megasonic excitation strength, hydrophobicity, and quality of particle/hole match using 1 mm-scale particles. Second is to demonstrate repeatable self-assembly into lithographically-defined shape-matched binding sites. Third is to relate the measured assembly yields to differences in binding energy in order to identify limits on selectivity and component size. Creating rapid, effective, widely-applicable nanomanufacturing technologies such as the one described here is important. There is a vast amount of existing research on nanocomponents, but more research on incorporating such nanocomponents into larger systems will be needed to convert them into practical systems and new products. Such systems could range from single electronics to physical, chemical, and biological sensors.