Collaborative Research: Intentionally Nonlinear Design of High-frequency Atomic Force Microscopy for Enhanced Material Characterization

自20世纪80年代初发展以来，原子力显微镜（AFM）一直是纳米和生物科学领域最有用的成像工具之一。该奖项支持一种新型AFM的理论和实验研究，这种新型AFM通过建设性地使用有意的非线性共振来实现，从而能够利用高频测量进行传感。除了证明在纳米/微米设计中建设性地利用有意非线性的概念以实现无法实现的性能的功效之外，从更广泛的意义上说，该项目的方法可以作为评估纳入复杂机械系统的强非线性如何导致大幅性能增益的测试平台。这项工作可能具有潜在的变革性，因为它可以提供一种基于高频传感的有意非线性AFM技术的新范式，并具有显着增强灵敏度和性能的能力。所获得的AFM传感能力将是纳米和生物科学等领域中无与伦比的工具。将对一种新的微悬臂梁设计进行详细的分析、计算和实验研究，从而实现更高频率的非线性AFM。在动态模式操作下，故意设计的1：n的内部共振之间的两个领先的弯曲模式的AFM微悬臂梁纳入内部硅桨，导致放大的高频谐波的桨响应，这是提高灵敏度的AFM的基础。研究团队将开发样品材料特性和形貌的显著增强的AFM测量，通过响应中的高次谐波传感实现。研究团队将通过理论研究来系统地研究、优化、扩展和验证这一有前途的概念，以表征桨对不同类型的相互作用力的响应，并将进行一系列扩展的实验测试，以评估高阶内部谐振设计对拓扑结构和材料特性变化的敏感性。此外，多桨原子力显微镜的设计，同时将多个内部共振进行定量表征分析，而相关的微细加工问题也将得到解决。

Since its development in the early 1980s, atomic force microscopy (AFM) has been one of the most useful imaging tools in the fields of nano- and biosciences. This award supports theoretical and experimental studies of a new type of AFM realized through constructive use of intentional nonlinear resonance enabling the utilization of high-frequency measurements for sensing. Apart from proving the efficacy of the concept of constructive utilization of intentional nonlinearity in nano/micro designs to achieve performance not otherwise attainable, in a broader sense this project's approach can act as a testbed for assessing how strong nonlinearity incorporated into a complex mechanical system can lead to drastic performance gains. This work can be potentially transformative, since it can provide a new paradigm of intentionally nonlinear AFM technology based on higher-frequency sensing, with demonstrated capacity for drastically enhanced sensitivity and performance. The gained AFM sensing capability will be an incomparable tool in fields such as nano- and bio-sciences.Detailed analytical, computational and experimental studies will be performed of a new, microcantilever beam design enabling higher-frequency nonlinear AFM. Under dynamic mode operation an intentionally designed 1:n internal resonance between the two leading bending modes of the AFM microcantilever incorporating an inner Silicon paddle, leads to magnification of high-frequency harmonics in the paddle response, which is the basis for AFM of improved sensitivity. The research team will develop the significantly enhanced AFM measurements of sample material properties and topography, achieved through sensing of higher harmonics in the response. The research team will systematically study, optimize, extend and validate this promising concept through theoretical studies to characterize the paddle's response to different types of interaction forces, and will perform an extended series of experimental tests to assess the sensitivity of high-order internal resonance designs to changes in topology and material properties. Moreover, multi-paddle AFM designs incorporating multiple simultaneous internal resonances will be analyzed for quantitative characterization, whereas related microfabrication issues will also be addressed.