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From the Preset Studies branch on the Select Study Type list, select a study—Stationary; Prestressed Analysis, Eigenfrequency; Prestressed Analysis, Frequency Domain; or Time Dependent Click Finish ().

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Add the materials, typically a solid and a dielectric. Note that it is important to select the appropriate material type (Solid or Non-solid) when adding the material in this physics interface.

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By default, the Electromechanics interface adds a Free Deformation node for the mesh displacements in the moving mesh and an Electrical Material Properties node for the non-solid dielectric on the domain level. An Electromechanical Interface and a Linear Elastic Dielectric node are also added by default, initially without any selections. If the solid material is, for example, insulating, add the solid domains to the Linear Elastic Dielectric node’s selection list. COMSOL Multiphysics solves the electrostatics equations within the Linear Elastic Dielectric, and there is also the option to add electrostrictive forces to the material. If the potential is constant inside the solid regions, so that it is not necessary to solve for the potential in these domains, add a Linear Elastic Material Model node and select the solid domains in this feature (an example where this is appropriate would be a metal held at constant potential). In both cases the Electromechanical Interface node automatically acquires the correct selection (at the interface between the solid and non-solid domains) as the selection of these features is changed. The Linear Elastic Dielectric feature automatically applies the appropriate volume forces to the material that result from the electric field, whilst the Electromechanical Interface feature adds surface forces that result from the electric field outside the solid regions.

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Verify that the default boundary conditions are correctly assigned for the three types of boundaries in the model: the Zero Charge node for all nonsolid dielectric boundaries (and a Prescribed Mesh Displacement node for zero mesh displacements on the same boundaries) and the Free node for all solid boundaries.

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Add additional boundary conditions as needed. Typically an Electric Potential node and a Ground node is required (alternatively Terminal nodes can be used if external circuits are to be added or if device impedance calculations are desired).

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Add physics nodes from the Physics toolbar, Domains, Boundaries submenus, for example. The solid domain needs constraints such as a Fixed Constraint at some boundary (available on the Structural submenu).

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To solve the problem, on the Study toolbar click Compute. The solver settings can require some adjustments depending on the characteristics of the model. In particular it is sometimes necessary to scale the variables separately as there are often large differences between the magnitudes of the electric potential and the displacements.