应用数学和力学(英文版)
應用數學和力學(英文版)
응용수학화역학(영문판)
APPLIED MATHEMATICS AND MECHANICS(ENGLISH EDITION)
2014年
5期
567-574
,共8页
capillary force%van der Waals force%adhesion force%curvatures probe shape
In micro-manipulation, the adhesion force has very important influence on behaviors of micro-objects. Here, a theoretical study on the effects of humidity on the adhesion force is presented between atomic force microscope (AFM) tips and substrate. The analysis shows that the precise tip geometry plays a critical role on humidity depen-dence of the adhesion force, which is the dominant factor in manipulating micro-objects in AFM experiments. For a blunt (paraboloid) tip, the adhesion force versus humidity curves tends to the apparent contrast (peak-to-valley corrugation) with a broad range. This paper demonstrates that the abrupt change of the adhesion force has high correla-tion with probe curvatures, which is mediated by coordinates of solid-liquid-vapor contact lines (triple point) on the probe profiles. The study provides insights for further under-standing nanoscale adhesion forces and the way to choose probe shapes in manipulating micro-objects in AFM experiments.