【摘要】 有关微观物体的粘附力与变形分析在微机械和表面物理中越来越重要.文章以表面形状由幂函数描述的轴对称微冲头与半空间体为研究对象,分析作用于微冲头上的分子间作用力和液桥张力,分析了在微观力作用下的微冲头接触前的弹性变形.最后以液桥张力作用力下微冲头的特例———微球为对象,分析了液桥体积对微冲头顶端竖向变形的影响.分析结果表明,小间距时,作用于微冲头顶端的液桥力随间距的增大而减小,并随液桥体积的增大而增大.在较大间距时,液桥力与液桥体积之间的关系却出现了一种波动现象,而在小间距时,微冲头的变形随液桥体积的增加而减小,同时随液桥体积变化而先增后减的波动,大间距时这种波动现象愈加明显.微冲头的粘附接触特性中出现的这种波动现象也说明了微观尺寸效应的存在.更多还原

【Abstract】 Analysis of the pressure distribution and deformation of a microstructure is important for micro-electro mechanical systems(MEMS) and surface physics.Here,a micro-punch whose shape follows a power function is presented.First, the intermolecular force on the micro punch was given and approximated with Maugis-Dugdale potential and also the liquid bridge forces.Second,the deformation in vertical direction of the Maugis-Dugdale micro punch was calculated.Finally,a special micro punch whose top shape is spherical was given and the influence of liquid bridge volume on its deformation pre-contact was studied.It was found that the relationship of micro punch deformation and two factors of liquid bridge volume fluctuates when the distance between micro punch and half-space is small,which shows the micro scale effect of MEMS.When the distance is larger,the deformation increases with the liquid bridge volume in general.更多还原