Deep understanding of the dependence between capillary adhesion behavior and meniscus Kelvin radius or interface micromorphology

Abstract

With the structure and device entering the micro/nano scale, the interaction between micro devices is mainly governed by the interface forces. The capillary adhesion force, as the main component of the interface force, significantly affects the detection accuracy and reliability of the micro/nano measurement system. In this paper, an accurate parameterized theoretical model of the capillary force related to relative humidity considering a non-constant Kelvin equilibrium radius, as well as a model with respect to surface roughness derived from a sinusoidal characteristic microtopography under the partially infiltrated state of surface microcosmic grooves are established which can more accurately describe the capillary adhesion behavior between real workpiece surfaces. A high-sensitivity force measurement system using the probe tip on micrometre scale is developed to measure capillary forces. The experiment results demonstrate the accuracy of the theoretical models and reveal the relationship between effective distance, rate of change of the capillary force with the relative humidity or surface roughness. This work will expand the scope of understanding of the interaction effects appeared on micrometer-scale probe tips and lead to many potential applications of the interface interaction in micro- and nanotechnology.