Thin-Film Damping
The MEMS Module also includes the Thin-Film Flow interface, which, when appropriately coupled with the Solid Mechanics interface, is equivalent to using the Thin-Film Damping boundary condition.
Use the Thin-Film Damping node to apply boundary loads to the surface of a resonator that result from squeeze-film or slide-film damping. Squeeze-film damping occurs when a thin film of gas is “squeezed” between two parallel plates, one of which is in motion normal to its surface. Slide-film damping occurs in similar situations except that the direction of motion of the moving plate is tangential to its surface. Examples of common situations in which these types of damping are appropriate are parallel-plate capacitive and comb-drive actuators for squeeze-film and slide-film damping, respectively. The thin-film damping boundary condition can accommodate general displacements of the moving plates specified by means of the Fluid-Film Properties node.
The Thin-Film Damping node is only available with some COMSOL products (see https://www.comsol.com/products/specifications/).
The Fluid-Film Properties node and the Border node are added by default. These additional subnodes are available: Fluid-Film Properties, Border, Inlet, Outlet, Wall, and Symmetry.
The Fluid-Film Properties, Inlet, Outlet, Border, Wall, and Symmetry nodes are all described for The Thin-Film Flow Interfaces in the MEMS Module User’s Guide.
Also see Theory for the Thin-Film Flow Interfaces in the MEMS Module User’s Guide as the Thin-Film Damping boundary condition is equivalent to an appropriately coupled Thin-Film Flow interface. Therefore, its theory is described in full for that physics interface.
Location in User Interface
Context Menus
Solid Mechanics>Mass, Spring, and Damper>Thin-Film Damping
Ribbon
Physics tab with Solid Mechanics selected:
Boundaries>Mass, Spring, and Damper>Thin-Film Damping