CAREER: Sub-NanoNewton Force Spectroscopy in Liquids with Dual-Frequency-Modulation AFM

本学院早期职业发展（CAREER）项目的研究目标是开发一种基于原子力显微镜（AFM）的纳米结构快速机械表征方法。 新方法将依赖于最近研究的控制方案概念，该概念使用两个自激振动信号来实现同步成像和三维力谱。 这项工作的重点是淹没在水中的结构，包括计算阶段和实验阶段。计算阶段包括表征过程中流体、AFM探针和样品的连续原子模拟，而实验阶段包括将新硬件并入现有显微镜、开发控制软件和调试用于模拟中相同样品的方法。 可供参考的材料包括一份描述基本组成部分、基本机制和控制方案的工艺规范;建模和分析工具，通过硬件进行演示和验证，研究结果文档，工程学生教育，以及第一代大学预科学生的工程研究经验。如果成功，这项工作的结果将扩大目前的AFM能力，使一些最微妙的生物样品在其天然的水环境中的特征，并将导致亚纳米机械性能的更系统、定量和快速的评估。 这将有助于纳米工程的倡议，如纳米纤维和纳米制造，这取决于设计的可控结构与明确的机械性能。 增强AFM来表征新的生物材料也将有利于生物和医学领域，如癌症研究，基因组学和细胞重建，这些领域的进步可以直接有助于提高人类的生活质量。 研究生和本科工程专业的学生和大学预科学生将受益于课堂教学和参与研究。

The research objective of this Faculty Early Career Development (CAREER) project is to develop a method for rapid mechanical characterization of nanoscale structures, based on atomic force microscopy (AFM). The new method will rely on a recently researched controls scheme concept that uses two self-excited vibration signals to enable simultaneous imaging and 3-dimensional force spectroscopy. The work focuses on structures submerged in water and consists of a computational and an experimental phase. The computational phase includes continuum-atomistic simulation of the fluid, AFM probe and sample during characterization, while the experimental phase includes incorporation of new hardware into an existing microscope, development of controls software and commissioning of the method for the same samples as in the simulations. Deliverables include a process specification describing fundamental components, basic mechanisms and controls schemes; modeling and analysis tools, demonstration and validation via hardware, documentation of research results, engineering student education, and engineering research experiences for first-generation pre-college students.If successful, the results of this work will broaden current AFM capabilities by enabling characterization of some of the most delicate biological samples in their native aqueous environment, and will lead to a more systematic, quantitative, and rapid evaluation of sub-nanometer mechanical properties. This will contribute to nanoscale engineering initiatives, such as nanofabrication and nanomanufacturing, which depend on the design of controllable structures with well-defined mechanical properties. The enhancement of AFM to characterize new biomaterials will also be beneficial in biological and medical fields like cancer research, genomics and cell reconstruction, where advances could directly contribute to improving the quality of life of human beings. Graduate and undergraduate engineering students and pre-college students will benefit through classroom instruction and involvement in the research.