Statistical Mechanics of Colloidal Particles in Optical Force Fields

*技术摘要*本项目将使用实验观测和理论研究相结合的方法来阐明布朗涡旋的性质，布朗涡旋是一种新发现的随机机器，它使用随机热力将能量转化为运动。传统的确定性机器浪费能量穿透波动，而随机机器则利用随机力来完成它们的热力学循环。与其他随机机器不同，布朗涡旋在静态力场中演化，该力场结合了保守的陷阱和非保守的驱动力。类似的系统被认为出现在生化、社会和金融网络中。发展对布朗旋涡工作原理的基本理解将为两名研究生提供博士学位论文，并为四名本科生物理专业提供荣誉论文。这个实验计划已经促进了第一个实用的拖拉机横梁和第一个结合力场的发展，这两个项目也都立即在现实世界中应用。*非技术摘要*我国的大部分技术都是基于基础机械的组合，如车轮、杠杆和螺丝。这个项目将阐明一种名为布朗旋涡的新型基本机的性质，它使用随机热噪声将能量转换为运动。该计划的基本目标是深入了解布朗涡旋是如何工作的，以及当它们在复杂系统中自然出现时如何识别和表征它们。该项目将为两名研究生提供博士学位论文，为四名本科生提供荣誉论文。这些学生将从事的实验利用了最先进的光学显微操作技术，其中计算机设计的全息图施加的力和扭矩被用来创造和驱动微观机器，既是为了提高基础知识，也是为了实际应用。

****Technical Abstract****This project will use a combination of experimental observations and theoretical investigations to elucidate the properties of Brownian vortexes, a newly discovered category of stochastic machines that use random thermal forces to transduce energy into motion. Whereas conventional deterministic machines waste energy punching through fluctuations, stochastic machines instead take advantage of random forces to work through their thermodynamic cycles. Unlike other stochastic machines, Brownian vortexes evolve in static force fields that combine conservative traps and non-conservative driving forces. Analogs of such systems are believed to occur in biochemical, social and financial networks. Developing a fundamental understanding of how Brownian vortexes work will provide doctoral dissertations for two graduate students and honors theses for four undergraduate Physics majors. This experimental program already has fostered the development of the first practical tractor beams and the first knotted force fields, both of which also have immediate real-world applications.****Non-Technical Abstract****Much of our nation's technology is based on combinations of elementary machines, such as wheels, levers and screws. This project will elucidate the properties of a new type of elementary machine called a Brownian vortex that uses random thermal noise to transform energy into motion. The program's fundamental goals are to develop a deep physical understanding of how Brownian vortexes work and how to recognize and characterize them when they arise naturally in complex systems. This program will provide doctoral disserations for two graduate students and honors theses for four undergraduate Physics majors. The experiments on which these students will work take advantage of state-of-the-art techniques of optical micromanipulation, in which the forces and torques exerted by computer-designed holograms are used to create and drive microscopic machines both to advance fundamental knowledge and also for practical applications.