NER: Torque Spectroscopy for Nanosystem Characterization and Fabrication

该项目是响应纳米尺度科学与工程计划，NSF 01-157， NER类。这项研究的目的是开发一种技术，以提供可调节的扭矩到纳米系统；这样的扭矩将在皮牛顿-纳米量级。具有角动量的螺旋结构光将用于光学捕获装置，以向捕获的粒子传递角动量，从而对捕获的物体施加扭矩。利用螺旋波前与平面波的干涉构成的俘获束，可以获得被困物体的位置和方向。本研究的重点是利用传统的单光束阱结构开发一种光阱；构建了必要的螺旋结构激光束模式作为拉盖尔-高斯（LG）光束模式，并构建了LG光束模式与平面波光束模式之间的干涉图。进行生物分子的扭矩光谱实验。候选分子有像肌球蛋白这样的盘绕蛋白，像纤维连接蛋白和腱蛋白这样的模块化基质蛋白，以及DNA双螺旋结构。这项研究计划将对知识、教育、工业和技术的进步产生广泛的影响。光力矩阱是纳米科学与工程综合发展的使能技术，在纳米技术从表征到制造等各个方面都有广泛的应用。在纳米尺度的生物系统中，它将被用来提供对单个分子行为的理解。对于纳米级结构，它将使表征依赖于旋转运动的新型纳米级结构和现象成为可能。最后，对于纳米级制造工艺，它将使新的纳米制造工艺成为可能，这些工艺将依赖于六维粒子的操纵。其他应用包括测量旋转纳米马达的扭矩和功率输出，测量分子的弯曲强度，测量纳米轴承的阻力，以及通过光子组件驱动纳米系统。该项目还将对研究生的新课程产生影响，将纳米科学和工程的工程和物理元素结合起来；纳米系统和纳米生物系统的研究；为本科生提供参与纳米技术研究项目的培训机会；工业合作为教师、研究人员和学生提供技术转让和培训机会。

This project was received in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NER. The purpose of this research is to develop the technology to deliver regulated torques to nanosystems; such torques would be on the order of piconewton-nanometers. Helicallv structured light possessing angular momentum will be used in an optical trapping arrangement to deliver angular momentum to trapped particles thereby applying a torque to the trapped object. Position and orientation of a trapped object will be achieved with a trapping beam constructed from the interference of a helical wave front and a plane wave. This research focuses on developing an optical trap using a conventional single-beam trap architecture; constructing the requisite helically-structured laser beam modes as Laguerre-Gaussian (LG) beam modes and constructing an interference pattern between LG beam modes and plane-wave beam modes. Torque spectroscopy experiments of biomolecules will be performed. Candidate molecules are coiled-coil proteins like myosin, modular matrix proteins like fibronectin and tenascin, and the DNA double helix.This research program will have a broad impact in the advancement of knowledge, education, industry and technology. An optical torque-trap is an enabling technology for the comprehensive development of nanoscience and engineering, and will have wide application in nanotechnology from characterization to fabrication. In nanoscale biosystems it would be used to provide an understanding of the behavior of single molecules. For nanoscale structures, it would enable the characterization of novel nanoscale structures and phenomena which depend upon rotary motion . Finally for nanoscale manufacturing processes it would enable new nanofabrication processes which would depend upon the manipulation of particles in six-dimensions Other applications include measuring the torque and power output of rotary nanomotors, measuring the bending strength of molecules, measuring the drag on nanobearings, and driving nanosystems by photonic components. This program will also have impacts in new curriculum for graduate students, combining elements of engineering and physics for nanoscience and engineering; the study of nanosystems and nanobiosystems; training opportunities for undergraduate students in nanotechnology through participation in research projects; and industrial collaboration providing technology transfer and training opportunities for faculty, research associates, and students.