NIRT: Nanoscale Directed Self-Assembly in Electrical and Optical Fields

美国特拉华州大学制造纳米结构材料或纳米设备肯定会采用自组装技术。特别是，溶液相自组装是创造功能纳米结构的生物学途径，有望以科学和经济上可行的方式发展工业纳米技术。设计微纳尺度的设备和纳米结构材料需要控制和理解纳米尺度的“积木”在溶液中自组装的热力学和动力学。这一过程本质上是分层次的，因此分子水平的物理和化学导致纳米粒子和溶剂分子之间的相互作用势，在适当的条件下，这些粒子可以组装成纳米到微米级的高阶结构，并具有紧急功能。然而，为了利用人工应用的自我组装，需要高水平的方向和控制。我们提出了一个综合的科学和教育计划，以开发使用定向自组装来制造纳米器件的新路线，并促进纳米制造领域的知识状态，包括快速传播我们的结果和更广泛的纳米技术培训。定向自组装是应用外场(即电学、光学和流动)来偏置或调制热力学和机械驱动力，以便以高选择性和高精度并行组装大量粒子。为了推动这项技术的发展，我们与来自三所大学的五名研究人员建立了合作伙伴关系，他们拥有互补的天赋和技能，结合起来可以开发出新的有价值的方法来理解和控制胶体和纳米级“积木”之间的相互作用，然后操纵这些物体来形成有用的结构、设备和原型纳米级制造方案。具体地说，我们提出了一个研究计划，主要是为了解决了解和控制纳米粒子和分子组装中的原子和分子相互作用的需要，以制造具有更高水平功能的新型自组装微结构。我们将开发能够控制分子到微米尺度的结构和动力学的实验技术，以及补充的理论建模和模拟。我们提出的研究的智力优势围绕着我们的实验、模拟和理论的整合，以进一步发展和严格测试纳米尺度上定向自组装的基本理解。例如，我们提出了一些特定的实验，在这种实验中，当暴露在介电泳力(交流电场)下时，几个模型胶体的图案化阵列将被光学镊子保持。无参数的斯托克斯动力学模拟将在逐个颗粒的基础上进行比较，以测试我们对介电定向组装背后的多体静电和流体动力力的理解，从而促进我们对实现外部控制组装的基本属性和工艺的了解。直接光学镊子的使用将能够直接测量颗粒之间的静态和动态相互作用，提供强大的新的颗粒表征方法。模拟、理论和实验将朝着组装更精细的积木的目标前进，这样这些方法就可以应用于纳米颗粒，甚至可能应用于蛋白质。这些研究结果将有助于基于定向自组装的制造工艺的合理设计、控制和优化，以及新材料的合成，如光子材料、纳米孔膜和生物传感器。这项工作有可能带来高额回报，因为触发、引导和控制纳米粒子在溶液中或表面上的大规模平行但高度选择性的组装，可以从具有工程意义的胶体、大分子和纳米粒子构建块创建真正的功能材料。我们工作的其他更广泛的影响包括教育工具、研讨会和短期课程的开发。将向学生和工业研究人员提供关于粒子科学和纳米制造技术的短期课程，以及关于定向自组装的新的基于网络的教学模块。这里提出的合作还为博士和本科生提供了在纳米技术领域工作的独特培训，为他们提供了合理、分层次的设计和制造的技能和背景。研究的结果将主要集中在可用于广泛行业的使能技能和技术。为了促进这项研究及其实际应用，建议建立一个产业伙伴关系。这项建议涉及纳米结构、新现象、量子控制和多尺度、多现象理论、建模和模拟等主题。

ABSTRACT - 0506701University of DelawareFabricating nanostructured materials or nanoscale devices will most certainly employ selfassembly. In particular, solution-phase self-assembly, which is the biological route to creating functional nanostructures, promises scientifically and economically viable ways to develop industrial nanotechnology. Engineering micro-to-nanoscale devices and nanostructured materials requires control and understanding of the thermodynamics and kinetics of self-assembly of nanoscale "building blocks" in solution. This process is hierarchical in nature, so that molecular-level physics and chemistry lead to interaction potentials between nanoparticles and solvent molecules, which under the right conditions can assemble into higher-order structures on the nano-to-micron scale with emergent functionality. However, to harness self-assembly for man-made applications a high level of direction and control are required. We propose an integrated scientific and educational program to develop novel routes using directed selfassembly to manufacture nanoscale devices and advance the state of knowledge in the field of nanoscale manufacturing, including both rapid dissemination of our results and broader nanotechnology training.Directed self-assembly is the application of external fields (i.e., electric, optical, and flow) to bias or modulate thermodynamic and mechanical driving forces in order to assemble large numbers of particles in parallel with high selectivity and precision. To advance this technology, we have created a partnership of five researchers from three universities who have complementary talents and skills that, in combination, can develop new and valuable approaches to understand and control the interactions between colloidal & nanometer scale "building blocks", and then to manipulate those objects to form useful structures, devices, and prototypical nanoscale manufacturing schemes. Specifically, we propose a research program primarily designed to address the need to understand and control atomic and molecular interactions in nanoparticles and molecular assemblies to manufacture novel self-assembled microstructures with higher levels of functionality. Experimental techniques capable of controlling molecular-to-micron scale structure and dynamics will be developed, along with complementary theoretical modeling and simulations.The intellectual merit of our proposed research revolves around our integration of experiment, simulation, and theory to further develop and rigorously test fundamental understanding of directed self assembly at the nanoscale. For example, we propose specific experiments whereby patterned arrays of a few, model colloids will be held by optical tweezers while exposed to dielectrophoretic forces (ac electric fields). Parameter-free Stokesian Dynamics simulations will be compared on a particle-by-particle basis to test our understanding of the many-body electrostatic and hydrodynamic forces underlying dielectrophoretic directed assembly, thereby advancing our knowledge about the fundamental properties and processes that enable externally controlled assembly. The use of directing optical tweezers will enable direct measurements of the static and dynamic interactions between particles, providing powerful new particle characterization methods. Simulation, theory and experiment will drive toward the goal of assembling ever finer building blocks such that the methods can be applied to nanoparticles, and perhaps, even to proteins. Results of these investigations should facilitate the rational design, control, and optimization of manufacturing processes based on directed self-assembly, as well as the synthesis of new materials, such as photonic materials, nanoporous membranes, and biosensors. This work offers the potential for high reward because triggering, directing, and controlling the massively parallel, but highly selective assembly of nanoscale particles in solution or on to surfaces can create truly functional materials from colloid, macromolecular and nanoparticle building blocks of engineering significance.Additional broader impacts of our work include the development of educational tools, workshops, and short courses. Short courses on particle science and nanoscale manufacturing techniques will be offered to students as well as to industrial researchers, along with new web-based teaching modules about directed self-assembly. The collaboration proposed herein also provides unique training for doctoral and undergraduate students to work in the field of nanotechnology, providing them with skills and background for rational, hierarchical design and fabrication. The outcome of the research will be primarily focused on enabling skills and techniques that can be used across a wide array of industries. An industrial partnership is proposed to facilitate the research and its practical applications.This proposal addresses the themes of Nanoscale Structures, Novel Phenomena, and QuantumControl and Multi-scale, Multi-phenomena Theory, Modeling and Simulation at the Nanoscale.