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

* 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根据什么原理利用分子混沌来工作的？这些问题的答案不仅可以提供对自然系统和过程的宝贵见解，而且可以为开发新技术提供基础。该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求这些答案，但其激励力量可以调整，其行为适合于详细分析。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移动而创建的。胶体颗粒？使用全息视频显微镜以非常高的分辨率测量三维运动，并使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，这种噪声驱动的微机械即使在静态力场中也能工作。对自然和人造微机器的激活和同步的深入了解应该来自对由胶体球和专门制作的光束产生的布朗涡旋的系统研究。 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。除了为这项研究计划提供动力外，对微观世界的全息控制将继续成为纽约大学科学前沿计划的中心舞台，这是一项K-12教育推广活动，将数百名纽约市的学童带到纽约大学进行动手实验室体验。技术摘要 * 该实验方案结合了全息光学捕获与全息视频显微镜，以探测通过非保守力场移动的单个和相互作用的胶体颗粒的统计物理。 光学显微操作技术的最新发展创造了新的机会，施加精确控制的力在显微纹理系统。 全息投影陷阱中的相位梯度可以产生一般违反机械能守恒的力和扭矩。 因此，在相位使能光阱中的胶体粒子构成了非平衡统计物理学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来测量纳米分辨率的光学捕获胶体颗粒的三维轨迹。全息光学陷阱将被设计为优化保守力和非保守力。由此产生的丰富的数据集将提供直接的见解，单粒子动力学，粒子间的相互作用，和驱动耗散稳态的多体集体行为。这个项目的每一个元素，从光诱导力的全息控制，到随机热机耦合阵列中的同步和熵产生，都涉及到解决突出的科学和技术问题。此外，为该项目开发的技术将继续成为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，将数百名纽约市的学童带到纽约大学进行实验室图尔斯之旅。

****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.