Wang Wenting, Zhang Kaidi, Zhang Wenhao, Hou Yaoping, Chen Yuhang
Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230027, People's Republic of China.
Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230027, People's Republic of China.
Nanotechnology. 2021 Apr 30;32(29). doi: 10.1088/1361-6528/abf37a.
To enhance contact resonance atomic force microscopy (CR-AFM) and harmonic AFM imaging simultaneously, we design a multifunctional cantilever. Precise tailoring of the cantilever's dynamic properties is realized by either mass-removing or mass-adding. As prototypes, focused ion beam drilling or depositing is used to fabricate the optimized structures. CR-AFM subsurface imaging on circular cavities covered by a piece of highly oriented pyrolytic graphite validates the improved CR frequency to contact stiffness sensitivity. The detectable subsurface depth and cavity radius increase accordingly by using the multifunctional cantilever. At the same time, the free resonance frequency of the second mode is tuned to an integer multiple of the fundamental one. Harmonic AFM imaging on polystyrene and low-density polystyrene mixture shows the improved harmonic amplitude contrast and signal strength on the two material phases. The multifunctional cantilever can be extended to enhance other similar AFM operation modes and it has potential applications in relevant fields such as mechanical characterization and subsurface imaging.
为了同时增强接触共振原子力显微镜（CR-AFM）和谐波原子力显微镜成像，我们设计了一种多功能悬臂梁。通过去除或添加质量来实现对悬臂梁动态特性的精确调整。作为原型，使用聚焦离子束钻孔或沉积来制造优化结构。在覆盖有一片高度定向热解石墨的圆形腔体上进行的CR-AFM亚表面成像验证了改进后的CR频率对接触刚度灵敏度的提升。使用多功能悬臂梁时，可检测的亚表面深度和腔体半径相应增加。同时，将第二模式的自由共振频率调整为基频的整数倍。在聚苯乙烯和低密度聚苯乙烯混合物上进行的谐波原子力显微镜成像显示了在两种材料相上改进后的谐波幅度对比度和信号强度。多功能悬臂梁可扩展以增强其他类似的原子力显微镜操作模式，并且在机械表征和亚表面成像等相关领域具有潜在应用。
