Department of Engineering Mechanics, AML, Tsinghua University, Beijing 100084, People's Republic of China.
Nanotechnology. 2012 Oct 19;23(41):415502. doi: 10.1088/0957-4484/23/41/415502. Epub 2012 Sep 27.
Carbon nanotube (CNT) probes offer improved imaging resolution in atomic force microscopy (AFM) and nanomanipulating devices due to their excellent mechanical properties and high aspect ratios. The basis of ascertaining scanning image quality using CNT probes is often centered on whether axial buckling has occurred or not. Here we explore the mechanical behavior and applicability of CNTs in surface scanning using molecular dynamics simulations in which the influence of van der Waals interactions is accounted for. Our results indicate the possible deleterious effects from van der Waals interaction dominated buckling of the probe, which is exacerbated by surface corrugations at the atomic scale. Under the premise that these issues can be surmounted, a cantilever model developed under known requirements for the structural characteristics of CNT probes is shown to be able to assess imaging fidelity. This model offers an effective guide to the selection and design of CNT probes for AFM.
碳纳米管(CNT)探针具有优异的机械性能和高纵横比,在原子力显微镜(AFM)和纳米操作设备中提供了更高的成像分辨率。使用 CNT 探针确定扫描图像质量的基础通常集中在是否发生轴向屈曲上。在这里,我们通过分子动力学模拟探索了 CNT 在表面扫描中的机械行为和适用性,其中考虑了范德华相互作用的影响。我们的结果表明,探针的范德华相互作用主导的屈曲可能会产生有害影响,而在原子尺度上的表面波纹则会加剧这种情况。在可以克服这些问题的前提下,根据 CNT 探针结构特征的已知要求开发的悬臂梁模型被证明能够评估成像保真度。该模型为 AFM 中 CNT 探针的选择和设计提供了有效的指导。