Sader John Elie
ARC Centre of Excellence in Exciton Science, School of Mathematics and Statistics, The University of Melbourne, Victoria 3010, Australia.
Rev Sci Instrum. 2020 Oct 1;91(10):103702. doi: 10.1063/5.0018599.
Interatomic-force measurements are regularly performed using frequency-modulation atomic force microscopy. This requires conversion of the observed shift in the resonant frequency of a force-sensing cantilever to the actual force experienced by its tip. Recently, Sader et al. [Nat. Nanotechnol. 13, 1088 (2018)] showed that this force conversion can be unreliable and proposed the inflection point test to identify valid and robust force data. Efficient and user-friendly algorithms are required for its routine practical implementation, which currently do not exist. Here, we (1) advance the theoretical framework of the inflection point test, (2) develop the required efficient algorithms for its complete automation, and (3) demonstrate the utility of this automation by studying two experimental datasets, in ultrahigh vacuum and liquid. The principal outcome of this report is the development of user-friendly software that integrates this automation with a standard force conversion methodology. This software provides the enabling technology for practitioners to now seamlessly perform robust nanoscale and interatomic-force measurements.
原子间力测量通常使用调频原子力显微镜进行。这需要将力敏悬臂梁共振频率的观测位移转换为其尖端实际所受的力。最近，萨德等人[《自然·纳米技术》13, 1088 (2018)]表明，这种力的转换可能不可靠，并提出了拐点测试来识别有效且稳健的力数据。其常规实际应用需要高效且用户友好的算法，而目前并不存在这样的算法。在此，我们（1）推进了拐点测试的理论框架，（2）开发了实现其完全自动化所需的高效算法，（3）通过研究超高真空和液体中的两个实验数据集来展示这种自动化的效用。本报告的主要成果是开发了用户友好的软件，该软件将这种自动化与标准力转换方法集成在一起。该软件为从业者提供了使能技术，使他们现在能够无缝地进行稳健的纳米级和原子间力测量。
