Colloidal Interactions and Collective Behavior in Non-Conservative Optical Force Fields

非保守光学力场中的胶体相互作用和集体行为

• 批准号: 0855741
• 负责人: David Grier
• 金额: $ 36万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855741&HistoricalAwards=false
• 关键词: Colloidal; Interactions; Collective; Behavior; Non

****NON-TECHNICAL ABSTRACT****How do molecular motors coordinate their movements to power our muscles? By what principles do such nanometer-scale machines exploit molecular chaos to do their work? Answers to these questions would not only provide valuable insights into natural systems and processes, but also could provide a basis for developing new technology. This research program seeks these answers through experimental studies on model systems that participate in the same physical processes, but whose motivating forces can be tuned and whose behavior lends itself to detailed analysis. These systems are created from very small microscopic particles (colloidal particles) moving through force fields exerted by computer-designed holograms. The colloidal particles? three-dimensional motions are measured with very high resolution using holographic video microscopy and analyzed using the latest developments in the theory of nonequilibrium statistical physics. Recently, this approach has revealed the existence of Brownian vortexes, noise-driven micromachines that do work even in quiescent force fields. Insights into activation and synchronization of natural and artificial micromachines should emerge from a systematic study of Brownian vortexes created from colloidal spheres and specifically crafted beams of light. The combination of holographic experimental techniques used in this project defines the state of the art in this field. In addition to powering this research program, holographic control over the microscopic world will continue to take center stage in New York University's Scientific Frontiers program, a K-12 educational outreach activity that brings hundreds of New York City schoolchildren to NYU for hands-on laboratory experiences.**** TECHNICAL ABSTRACT****This experimental program combines holographic optical trapping with holographic video microscopy to probe the statistical physics of individual and interacting colloidal particles moving through non-conservative force fields. Recent developments of optical micromanipulation techniques have created new opportunities to exert precisely controlled forces on microscopically textured systems. Phase gradients in holographically projected traps can give rise to forces and torques that generically violate conservation of mechanical energy. Colloidal particles in phase-enabled optical traps therefore constitute an exceptionally flexible test-bed for new ideas in nonequilibrium statistical physics. The experimental program will exploit new methods of holographic video microscopy to measure the three-dimensional trajectories of optically trapped colloidal particles with nanometer resolution. The holographic optical traps will be designed to optimize both conservative and non-conservative forces. The resulting rich data sets will provide direct insights into the single-particle dynamics, inter-particle interactions, and many-body collective behavior of driven dissipative steady states. Each element of this project, from holographic control of light-induced forces, to synchronization and entropy production in coupled arrays of stochastic heat engines involves the resolution of outstanding scientific and technological questions. The techniques developed for this program, furthermore, will continue to take center stage in New York University's Scientific Frontiers program, a K-12 educational outreach activity that brings hundreds of New York City schoolchildren to NYU for hands-on laboratory tours.

*非技术摘要*分子马达如何协调它们的运动来为我们的肌肉提供动力？这种纳米级的机器是通过什么原理来利用分子混沌来完成他们的工作的？对这些问题的回答不仅将提供对自然系统和过程的宝贵见解，还可能为开发新技术提供基础。这项研究计划通过对参与相同物理过程的模型系统进行实验研究来寻找这些问题的答案，但这些模型系统的激励力可以调整，其行为有助于详细分析。这些系统是由非常小的微观粒子(胶体粒子)通过计算机设计的全息图施加的力场创建的。胶体颗粒？用全息视频显微镜以非常高的分辨率测量三维运动，并利用非平衡统计物理理论的最新发展进行分析。最近，这种方法揭示了布朗涡旋的存在，这种由噪音驱动的微型机器即使在静止的力场中也能工作。对胶体球体和专门制作的光束产生的布朗旋涡进行系统研究，应该可以洞察到天然和人造微型机器的激活和同步。该项目中使用的全息实验技术的组合定义了该领域的最新技术。除了为这一研究项目提供动力外，对微观世界的全息控制还将继续成为纽约大学科学前沿项目的中心，这是一项从K-12的教育推广活动，将数百名纽约市小学生带到纽约大学进行动手实验室体验。这个实验项目将全息光学捕捉与全息视频显微镜相结合，探索单个和相互作用的胶体粒子在非保守力场中运动的统计物理。光学微操作技术的最新发展创造了在显微纹理系统上施加精确控制力的新机会。全息投射陷阱中的相位梯度可能会产生力和力矩，这通常会违反机械能守恒定律。因此，位相使能光学陷阱中的胶体粒子构成了非平衡统计物理新思想的异常灵活的试验台。该实验计划将利用全息视频显微镜的新方法，以纳米分辨率测量光学捕获的胶体颗粒的三维轨迹。全息光学陷阱的设计将优化保守和非保守的作用力。由此产生的丰富的数据集将提供对单粒子动力学、粒子间相互作用和驱动耗散稳态的多体集体行为的直接见解。这个项目的每一个元素，从全息控制光诱导力，到随机热机耦合阵列中的同步和熵产生，都涉及解决悬而未决的科学和技术问题。此外，为该项目开发的技术将继续占据纽约大学科学前沿项目的中心舞台，该项目是一项K-12教育推广活动，将数百名纽约市学童带到纽约大学进行动手实验室之旅。