2024 年 18 巻 1 号 p. JAMDSM0002
Understanding the factors that determine friction between different materials is challenging due to the dependence of the friction coefficient on various surface and environmental conditions. This study investigates the correlation between the surface strain and friction force distributions on a microdevice driven by a comb actuator. The microdevice, designed to induce surface strain, was fabricated and mounted on the sample stage of an atomic force microscope (AFM). Friction force microscopy (FFM) measurements were performed within a 4.7 μm × 4.7 μm region where strain distribution was generated. A reduction in friction force was observed in regions corresponding to high surface strain in the friction direction, as indicated through finite element method (FEM)-based elastic analysis. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of an SiO2 film on the microdevice surface, suggesting that changes in interatomic distances between SiO2 surfaces with the same crystal structure influenced the variation in friction. Within the region where FEM analysis calculated a strain of 0.4-0.6%, a reduction in friction force ranging from 5% to 7% was observed.
