The MEMS Module User’s Guide gets you started with modeling MEMS systems using COMSOL Multiphysics. The information in this guide is specific to this module. Instructions how to use COMSOL in general are included with the
COMSOL Multiphysics Reference Manual.
Creating and Analyzing MEMS Models familiarizes you with modeling procedures useful when working with this module and MEMS applications such as microactuators and microsensors. Because the module is fully integrated with COMSOL Multiphysics, the design and analysis process is similar to the one you use in the base environment. The MEMS-specific modeling aspects should prove valuable during the modeling phase. There is also a short section (with model examples) about the materials databases available with this module.
AC/DC Interfaces chapter describes the physics interfaces for modeling conducting and nonconducting materials, including the enhanced versions of the Electrostatics and Electric Currents interfaces. It also has all the information about the Electrical Circuit interface. The Magnetic Fields interface is also included as part of the COMSOL Multiphysics base package, but this is detailed in the
COMSOL Multiphysics Reference Manual.
The Thin-Film Flow Interfaces (in the
CFD Module User’s Guide) can be added either singularly or in combination with other physics interfaces such as mass and energy transfer. The Thin-Film Flow interface is for 2D, 2D axisymmetric and 3D models, and the Thin-Film Flow, Domain interface is for 2D models.
The Fluid–Solid Interaction Interface (in the
Structural Mechanics Module User’s Guide) is an interface found under the Fluid Flow branch. It has the equations and physics for fluid-structure interaction, solving for the displacements, fluid velocity, and fluid pressure. Both the fluid loading on the structure and the structural velocity transmission to the fluid can be taken into account. From the Laminar Flow (the default) and Solid Mechanics submenus on the solid and boundary level you can access materials, sources, loads, and boundary conditions for the individual physics interfaces.
The Solid Mechanics Interface (in the
Structural Mechanics Module User’s Guide) has the equations and physics features for stress analysis and general linear solid mechanics, solving for the displacements.
The Thermal Stress, Solid Interface (in the
Structural Mechanics Module User’s Guide) combines Solid Mechanics and Heat Transfer for modeling stress analysis and general linear and nonlinear solid mechanics by solving for the displacements.
The Joule Heating and Thermal Expansion Interface (in the
Structural Mechanics Module User’s Guide) combines solid mechanics using a thermal linear elastic material with an electromagnetic Joule heating model. This is a multiphysics combination of solid mechanics, electric currents, and heat transfer for modeling of, for example, thermoelectromechanical (TEM) applications.
The Electromechanics, Solid Interface (in the
Structural Mechanics Module User’s Guide) combines solid mechanics and electrostatics with a moving mesh to model the deformation of electrostatically actuated structures. The physics interface is also compatible with piezoelectric materials.
The Electromechanics, Boundary Elements Interface (in the
Structural Mechanics Module User’s Guide) combines solid mechanics and electrostatics with a moving mesh to model the deformation of electrostatically actuated structures. The coupling is a boundary load caused by the Maxwell Stress at the interface of the solid domains and nonsolid voids, where the electric field is computed using the boundary element method. The backward coupling to Electrostatics is due to the deformations of the boundaries.
The Piezoelectricity, Solid Interface (in the
Structural Mechanics Module User’s Guide) combines piezoelectricity with solid mechanics and electrostatics for modeling of piezoelectric devices where all or some of the domains contain a piezoelectric material. The piezoelectric coupling can be on stress-charge or strain-charge form.
The Pyroelectricity Interface combines heat transfer in solids and electrostatics together with the constitutive relationships required to model pyroelectricity. Both the direct pyroelectric and inverse electrocaloric effects can be modeled.
The Piezoelectricity and Pyroelectricity Interface combines solid mechanics, electrostatics, and heat transfer in solids together with the constitutive relationships required to model piezoelectric applications, in which the temperature variation and electric charge are coupled.
The Thermoelasticity Interface combines the Solid Mechanics and Thermal Stress interfaces, together with the thermoelastic coupling terms. These coupling terms result in local cooling of material under tension and heating of material that is compressed. The resulting irreversible heat transfer between warm and cool regions of the solid produces mechanical losses, which can be important, particularly for small structures.
The Piezoresistivity, Domain Currents Interface is appropriate for situations when the thickness of the conducting and piezoresistive layers are both resolved by the mesh.
The Piezoresistivity, Boundary Currents Interface should be used when the thicknesses of the conducting and piezoresistive layers are much smaller than those of the structural layers (this is often the case in practice).
The Piezoresistivity, Shell Interface is used when the structural layer is thin enough to be treated by the shell interface, but the conducting and piezoresistive layers are still much thinner than the structural layers.
The Piezoresistivity, Layered Shell Interface combines structural layered shells with electric currents in shells to simulate the piezoresistive effect in multilayer structures. This physics interface requires the addition of the Composite Materials Module.
