A measurement technology of micro-topography of liquid surface and its application to evaluating micro buoyancy and surface tension

An improved moire method is developed. The Micro 3-D topography of curved liquid surface caused by small objects floating on it can be measured with this method. The micro buoyancy and surface tension can be further investigated from the obtained 3-D topography. 3-D topography of curved liquid surface caused by coins with different size is measured, the surface tension and buoyancy are analysized based on the 3-D topography. The obtained results show that coins floating on water is supplied by both the surface tension and buoyancy, especially buoyancy playing an essential role. The validation tests verify that the proposed method is feasible in 3-D topography measurement and quantitative analysis of the micro surface tension and buoyancy force.