Smart Surface Structures Group, Flinders Centre for NanoScale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia.
Nanotechnology. 2012 Jul 20;23(28):285704. doi: 10.1088/0957-4484/23/28/285704. Epub 2012 Jun 25.
A calibration method is presented for determining the spring constant of atomic force microscope (AFM) cantilevers, which is a modification of the established Cleveland added mass technique. A focused ion beam (FIB) is used to remove a well-defined volume from a cantilever with known density, substantially reducing the uncertainty usually present in the added mass method. The technique can be applied to any type of AFM cantilever; but for the lowest uncertainty it is best applied to silicon cantilevers with spring constants above 0.7 N m(-1), where uncertainty is demonstrated to be typically between 7 and 10%. Despite the removal of mass from the cantilever, the calibration method presented does not impair the probes' ability to acquire data. The technique has been extensively tested in order to verify the underlying assumptions in the method. This method was compared to a number of other calibration methods and practical improvements to some of these techniques were developed, as well as important insights into the behavior of FIB modified cantilevers. These results will prove useful to research groups concerned with the application of microcantilevers to nanoscience, in particular for cases where maintaining pristine AFM tip condition is critical.
提出了一种用于确定原子力显微镜（AFM）悬臂梁弹性常数的校准方法，这是对已建立的克利夫兰附加质量技术的改进。聚焦离子束（FIB）用于从具有已知密度的悬臂梁上去除一个定义明确的体积，从而大大降低了附加质量方法中通常存在的不确定性。该技术可应用于任何类型的 AFM 悬臂梁；但为了获得最低的不确定性，最好将其应用于弹性常数高于 0.7 N m^(-1)的硅悬臂梁，在这种情况下，不确定性通常在 7%至 10%之间。尽管从悬臂梁上移除了质量，但所提出的校准方法不会损害探头获取数据的能力。为了验证该方法中的基本假设，已经对该技术进行了广泛的测试。将该方法与许多其他校准方法进行了比较，并对其中一些技术进行了实际改进，以及对 FIB 修饰的悬臂梁的行为有了重要的了解。这些结果将对关注将微悬臂梁应用于纳米科学的研究小组有用，特别是在保持原始 AFM 尖端状态至关重要的情况下。
