AFM at the Macroscale: Methods to Fabricate and Calibrate Probes for Millinewton Force Measurements
AFM at the Macroscale: Methods to Fabricate and Calibrate Probes for Millinewton Force Measurements
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DOI：
10.1007/s11249-019-1134-2
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发表时间：
2019-01
影响因子：
3.2
通讯作者：
Nikolay T Garabedian;H. S. Khare;R. Carpick;D. Burris
中科院分区：
文献类型：
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作者：
Nikolay T Garabedian;H. S. Khare;R. Carpick;D. Burris
迄今为止，检测和控制纳米尺度和宏观尺度摩擦学体系之间的差距中的力的困难限制了基本原子尺度见解在实际摩擦和磨损控制中的应用。本文介绍了方法来实现和量化毫牛顿力测量原子力显微镜（AFM）使用现有的实验工具。我们将胶体微球安装在商业AFM杠杆的不同点上，以将其有效弯曲长度从125 µm减少到21至107 µm。基于直接校准的弹簧常数从100到10，000 N/m不等。在商业AFM（Dimension 3100）内，这些杠杆产生0.006和0.430 mN/V之间的法向力校准常数;即，将弹簧常数增加100倍会导致校准常数相应增加，但V/m灵敏度的增加微不足道。我们通过测量胶体和单晶MoS 2之间的摩擦来展示这些新功能，所施加的法向力高达3.4 mN，这在现有摩擦计的范围内，远高于AFM测量中通常使用的力。这些方法，利用完善的程序，只需要一个修改后的AFM悬臂，旨在为其他研究人员使用的平台，为纳米级和宏观尺度摩擦学之间的差距差距。
The difficulty in detecting and controlling forces in the gap between the nanoscale and macroscale tribometry regimes has so far limited the application of fundamental atomic-scale insights to practical friction and wear control. This paper describes methods to achieve and quantify millinewton forces measured by atomic force microscopy (AFM) using existing experimental tools. We mounted colloidal microspheres at different points along the span of commercial AFM cantilevers to reduce their effective flexural length from 125 µm to between 21 and 107 µm. The resulting spring constants, based on direct calibration, varied from 100 to 10,000 N/m. Within a commercial AFM (Dimension 3100), these cantilevers produced normal force calibration constants between 0.006 and 0.430 mN/V; i.e., increasing the spring constant by 100 × caused a corresponding increase in the calibration constant but only a negligible increase in V/m sensitivity. We demonstrate these new capabilities by measuring friction between the colloids and single-crystal MoS2at applied normal forces up to 3.4 mN, which is in the range of existing tribometers and well above the forces typically used in AFM-based measurements. These methods, which make use of well-established procedures and only require a modified AFM cantilever, are intended for use by other researchers as a platform for bridging the gap between nanoscale and macroscale tribometry.