Adhesion of a Micro Double Cantilever Beam Driven by Capillary Forces

Capillary forces present during the manufacturing and operation of microelectromechanical structures have been shown to cause collapse of these structures. Once collapsed these structures may permanently adhere together. In this paper we study the adhesion of a microstructure represented by a double cantilever beam (DCB); such adhesion is driven by both the capillary forces from a liquid droplet located between the DCB and the adhesion forces between the solids. The DCB is modeled using both a beam theory that accounts for geometrical nonlinearity and the linearized beam theory. This model rigorously couples DCB deformation, capillary forces, meniscus movement and adhesion, and reveals four dimensionless parameters that govern the adhesion problem. How changes in these parameters influence the capillary forces, the length of the contact zone, and the contact force is discussed in detail.