Model-Based Identification of Nanomechanical Properties in Atomic Force Microscopy: Theory and Experiments
Model-Based Identification of Nanomechanical Properties in Atomic Force Microscopy: Theory and Experiments
复制标题
原子力显微镜中基于模型的纳米力学特性识别：理论与实验
DOI：
10.1109/tcst.2018.2847644
复制
发表时间：
2019
影响因子：
4.8
通讯作者：
K. Pettersen
中科院分区：
文献类型：
--
作者：
Michael R. P. Ragazzon;J. Gravdahl;K. Pettersen
原子力显微镜 (AFM) 解析高精度相互作用力的能力使其成为确定软样品纳米力学特性的越来越流行的工具。传统上，弹性是通过收集力-距离曲线来确定的。最近，诸如粘弹性之类的动态特性可以通过悬臂的单频或多频调制将可观测值与样品特性相关联来确定。在本文中，提出了一种用于解析纳米力学特性的基于模型的技术。样品和悬臂均由动态模型表示。然后采用递归最小二乘法来识别样本模型的未知参数，从而揭示其纳米力学特性。本文提出了两个示例模型，展示了交换示例模型以最适合所研究材料的能力。该方法已在商业 AFM 上进行实验实施，用于在线估计弹性模量、弹簧常数和阻尼系数。此外，实验结果证明了使用所提出的方法测量随时间或空间变化的参数的能力。
The ability of the atomic force microscope (AFM) to resolve highly accurate interaction forces has made it an increasingly popular tool for determining nanomechanical properties of soft samples. Traditionally, elasticity is determined by gathering force–distance curves. More recently, dynamic properties such as viscoelasticity can be determined by relating the observables to sample properties, either by singlefrequency or multifrequency modulation of the cantilever. In this paper, a model-based technique for resolving nanomechanical properties is presented. Both the sample and cantilever are represented by dynamic models. A recursive least squares method is then employed to identify the unknown parameters of the sample model, thus revealing its nanomechanical properties. Two sample models are presented in this paper, demonstrating the ability to swap sample models to best suit the material being studied. The method has been experimentally implemented on a commercial AFM for online estimation of elastic moduli, spring constants, and damping coefficients. In addition, the experimental results demonstrate the capability of measuring time- or space-varying parameters using the presented approach.