MRI-R2: Development of a Correlation Force Spectrometer

MRI-R2：相关力谱仪的开发

• 批准号: 0959228
• 负责人: William Ducker
• 金额: $ 66.12万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-15 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0959228&HistoricalAwards=false
• 关键词: MRI; R2; Development; Correlation; Force

0959228Ducker"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."An improved understanding of the nanometer-scale motion of fluids is central to the development of our understanding of complex fluids and biomolecules. The PI proposes to develop an instrument that measures the forces acting during the natural motion of molecules and fluids, with capabilities that exceed all current instruments. This instrument will measure the correlated motion of two antiparallel cantilevers that have atomic force microscope (AFM) tips or colloidal spheres attached to the free ends. The fluid between the tips will couple the two cantilevers such that the correlated motion is sensitive only to the intervening fluid. This antiparallel arrangement will greatly diminish the contribution of the cantilevers compared to conventional AFM. Measurement of the correlated motion results in a large increase in signal-to-noise ratio because the correlation is not sensitive to electronic, optical or mechanical disturbances on individual cantilevers. Moreover, even the thermal noise on the individual cantilever is not part of the correlation signal, so the instrument will have a lower noise floor than is theoretically possible for existing single cantilever AFM techniques. The instrument will be capable of measuring the mechanical properties of individual molecules tethered between the two cantilevers, as well as the viscoelastic properties of complex fluids with nanometer resolution at frequencies up to hundreds of kHz. Also, the simplicity of the mechanical concept provides a relatively easy path for ultimate development of an inexpensive and small instrument.

0959228Ducker“该奖项是根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金的。”加深对流体纳米级运动的理解对于发展我们对复杂流体和生物分子的理解至关重要。 PI 提议开发一种仪器，用于测量分子和流体自然运动过程中作用的力，其功能超过所有现有仪器。该仪器将测量两个反平行悬臂的相关运动，悬臂的自由端连接有原子力显微镜 (AFM) 尖端或胶体球。尖端之间的流体将耦合两个悬臂，使得相关运动仅对介入的流体敏感。与传统的 AFM 相比，这种反平行布置将大大减少悬臂的贡献。相关运动的测量导致信噪比大幅增加，因为相关性对各个悬臂上的电子、光学或机械干扰不敏感。此外，即使单个悬臂梁上的热噪声也不是相关信号的一部分，因此该仪器的本底噪声将低于现有单悬臂梁 AFM 技术理论上可能达到的水平。该仪器将能够测量两个悬臂之间束缚的单个分子的机械特性，以及在高达数百kHz的频率下以纳米分辨率测量复杂流体的粘弹性特性。此外，机械概念的简单性为最终开发廉价且小型的仪器提供了相对简单的途径。