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

****非技术摘要****分子马达是如何协调运动来为我们的肌肉提供动力的？这种纳米级机器利用分子混沌来完成工作的原理是什么？这些问题的答案不仅可以为自然系统和过程提供有价值的见解，而且可以为开发新技术提供基础。该研究项目通过对参与相同物理过程的模型系统的实验研究来寻求这些答案，但其驱动力可以调整，其行为可以进行详细分析。这些系统是由非常小的微观粒子（胶体粒子）在计算机设计的全息图施加的力场中运动而形成的。胶体粒子？三维运动用全息视频显微镜以非常高的分辨率测量，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，这是一种噪声驱动的微机器，即使在静态力场中也能工作。对自然和人工微机器的激活和同步的见解，应该从对由胶体球和特制光束产生的布朗漩涡的系统研究中得到。在这个项目中使用的全息实验技术的组合定义了这个领域的艺术状态。除了为这个研究项目提供动力外，对微观世界的全息控制将继续成为纽约大学科学前沿项目的中心，这是一项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体验。****技术摘要****这个实验程序结合了全息光学捕获和全息视频显微镜来探测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为在微观纹理系统上施加精确控制的力创造了新的机会。相位梯度在全息投影陷阱可以产生力和扭矩，一般违反机械能守恒。因此，相位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。该实验项目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。全息光学陷阱将被设计为优化保守力和非保守力。由此产生的丰富数据集将提供对驱动耗散稳态的单粒子动力学，粒子间相互作用和多体集体行为的直接见解。这个项目的每一个要素，从光致力的全息控制，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，为这个项目开发的技术将继续在纽约大学的科学前沿项目中占据中心位置，这是一项K-12教育推广活动，吸引了数百名纽约市学生到纽约大学进行动手实验室参观。

****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.