CAREER: Joint Topographic Imaging and Materials Characterization using Atomic Force Microscopy - a Systems Approach

职业：使用原子力显微镜进行联合形貌成像和材料表征 - 一种系统方法

• 批准号: 1149860
• 负责人: Aditya Ramamoorthy
• 金额: $ 41.37万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1149860&HistoricalAwards=false
• 关键词: CAREER; Joint; Topographic; Imaging; Materials

The atomic force microscope (AFM) is an instrument that allows the interrogation and manipulation of matter at the atomic scale and has revolutionized science and engineering. AFM based nano-interrogation includes, topographic imaging where one is interested in recreating an image of a sample, and material characterization where one wishes to determine intrinsic material properties. The primary drawback of AFMs is their low speed especially when interrogating soft matter, e.g., polymers and biological samples. This research involves the study of advanced signal processing algorithms that will allow simultaneous topographic imaging and materials characterization at ultra-high speeds and high fidelity. This will significantly accelerate the knowledge discovery process in domains such as material science, where the focus is often on fast evaluation of new materials. The investigator will promote cross-fertilization of ideas between the signal processing and the AFM communities by organizing joint workshops. The findings will be integrated into the curriculum via lab components and modules.The AFM uses a cantilever with a sharp tip that deflects based on inter-atomic forces; interrogation is performed by sensing and interpreting this deflection signal. This research focuses on the dynamic mode operation (the preferred mode for interrogating soft material), where the cantilever is typically excited sinusoidally and gently taps the medium. Current methods work by analyzing the steady state cantilever trajectory and are fundamentally limited in speed by the time-constants of the cantilever dynamics. This research will study order-of-magnitude improvements in speed by leveraging (a) the systems viewpoint and (b) newer AFM techniques such as multi-frequency excitation. Signal processing algorithms for simultaneously detecting topographic features and/or material property changes will be studied and exhaustively tested on experimental data.

原子力显微镜（AFM）是一种仪器，可以在原子量表上审问和操纵物质，并彻底改变了科学和工程。基于AFM的纳米插入包括对重新创建样品图像感兴趣的地形成像以及希望确定内在材料特性的物质表征。 AFMS的主要缺点是它们的低速，尤其是在询问软物质时，例如聚合物和生物样品时。这项研究涉及对高级信号处理算法的研究，这些算法将允许以超高速度和高忠诚度同时进行地形成像和材料表征。这将大大加快诸如材料科学之类的领域的知识发现过程，在材料科学上，重点通常放在对新材料的快速评估上。研究人员将通过组织联合研讨会来促进信号处理与AFM社区之间思想的交叉施肥。这些发现将通过实验室组件和模块整合到课程中。AFM使用的悬臂具有尖锐的尖端，可根据原子间力偏转；询问是通过传感和解释此挠度信号来执行的。 这项研究的重点是动态模式操作（询问软材料的首选模式），其中悬臂通常会在正弦曲线上激发，并轻轻轻按培养基。 当前方法通过分析稳态悬臂轨迹来起作用，并从根本上受到悬臂动力学的时构的限制。这项研究将通过利用（a）系统观点和（b）较新的AFM技术（例如多频激发）来研究速度的速度顺序提高。用于同时检测地形特征和/或材料属性更改的信号处理算法将在实验数据上进行详尽的研究。