Accurately measuring the coefficient of friction (COF) is the fundamental prerequisite of superlubricity research. This study aimed to reduce the COF measurement resolution Δμ of atomic force microscopy (AFM). Based on the theoretical model, a distinctive strategy was adopted to reduce Δμ by optimizing the cantilever’s cross-section of the AFM probe, inspired by civil engineering. Δμ can be reduced by decreasing the width of the horizontal side w_R and the wall thickness t and increasing the width of the vertical side w_H. Moreover, the I-shape demonstrates the highest reduction in Δμ, followed by the U-shape. Considering the processability, the AFM probe with the U-shaped cross-sectional cantilever was investigated further, and the dimensions are 35 µm w_R, 3.5 µm w_H, 0.5 µm t, 50 µm l (cantilever length), and 23 µm h_tip (tip height). The finite element analysis results confirm its reliability. After being fabricated and calibrated, the AFM probe achieves the minimal Δμ of 1.9×10⁻⁶ under the maximum normal force so far. Additionally, the friction detection capability of the fabricated AFM probe improves by 78 times compared to the commercial tipless-force modulation mode (TL-FM) AFM probe with the conventional solid rectangular cross-sectional cantilever. This study provides a powerful tool for measuring 10⁻⁶ COF.

准确测量摩擦系数（COF）是超润滑研究的基本前提。本研究旨在降低原子力显微镜（AFM）的COF测量分辨率Δμ 。基于理论模型，受土木工程的启发，采用了一种独特的策略，通过优化 AFM 探针的悬臂横截面来减小 Δ μ 。 Δμ可以通过减小水平边的宽度w _R和壁厚t并增加垂直边的宽度w _H来减小。此外，I 形的 Δ μ降低幅度最大，其次是 U 形。考虑到加工性能，进一步研究了U形截面悬臂梁的AFM探针，尺寸为35 µm w _R、3.5 µm w _H、0.5 µm t、50 µm l（悬臂长度）和23 µm h_尖端（尖端高度）。有限元分析结果证实了其可靠性。经过制作和校准后，AFM探针在迄今为止最大法向力下实现了1.9×10 ^-6的最小Δμ 。此外，与具有传统实心矩形横截面悬臂梁的商用无尖端力调制模式（TL-FM）AFM探针相比，所制造的AFM探针的摩擦检测能力提高了78倍。这项研究为测量 10 ^-6 COF 提供了强大的工具。