Abstract: Contact problem of two particles has been a crucial research topic in the Micro Electro mechanical system.The capillary condensationis important in the microscopic.So it is inevitable to investigate the micro liquid bridge problem in the study of the nanoscale objects interaction forces.Based on the mechanical equilibrium,toroidal approximation,volume conservation and accurate mathematical methods,this paper develops a model to study the capillarybridge between two spherical microparticles,and analyses the influences of the contact angle on the liquid bridge rupture distance.It shows that the liquid bridge rupture distance decreases with the increasing contact angle as the capillaryforce is small,while it increases with increasing contact angle as the capillary force is large.The contact angle has a direct decisive effect on the rupture distance.The simulation results are useful for the prediction of the interactionforce,the property and the mechanism of the microparticles.

Key words: microparticle, capillary bridge, rupture distance