Thermoelastic Damping in a MEMS Resonator
Thermoelastic damping, which arises when you subject a material to cyclic stress, is an important factor when designing MEMS resonators. The stress brings about deformation, where materials heat under compressive stress and cool under tensile stress. Thus, due to the resulting heat flux, energy is lost to bring about this damping. The magnitude of the energy loss depends on the vibrational ...
Microresistor Beam
This example illustrates the ability to couple thermal, electrical, and structural analysis in one model. This particular application moves a beam by passing a current through it; the current generates heat, and the temperature increase leads to displacement through thermal expansion. The model estimates how much current and increase in temperature are necessary to displace the beam. Although ...
Electromagnetic Force Calculation Using Virtual Work and Maxwell Stress Tensor
The model compare the electromagnetic force calculated by *virtual work* and *maxwell stress tensor* methods on the axial magntic bearing. The forces is evaluated by studying the effect of a small displacement on the electromagnetic energy of the system. This is done by using the *Magnetic Fields*, *Deformed Geometry* and *Sensitivity* physics interfaces.
Residual Stress in a Thin Film Resonator - 3D
Surface micromachined thin films are often subject to residual stress. This COMSOL Multiphysics example describes a thin film resonator with straight or folded cantilever beam springs. The resonance frequencies of the resonator are affected by thermal stress. Using folded springs relieves this effect. The example is made up of four models: two thin film resonators with folded cantilever beam ...
Piezoceramic Tube
This example involves a static 2D axisymmetric analysis of a piezoelectric actuator using the Piezoelectric Devices physics interface. It models a radially polarized piezoelectric tube, as described by S. Peelamedu and co-authors. An application area where radially polarized tubes are employed is in nozzles for fluid control in inkjet printers.
Piezoelectric Microgripper
This tutorial models a piezoelectrically actuated microgripper with mechanical contact. The microgripper contains a piezoelectric actuator that operates in the longitudinal mode. Elongation in the longitudinal direction creates a lifting movement to the structure. Simultaneous contraction in the transversal direction closes the gripper and allows it to move objects. The model uses the ...
Prestressed Micromirror
One method of creating spring-like structures or inducing curvature in thin structures is to plate them to substrates that are under the influence of residual stresses. The plating process can control this stress even for similar materials. One such device is the electrostatically controlled micromirror. It is typically quite small, and arrays of such devices can be implemented in projectors. ...
Piezoelectric Rate Gyroscope
This model shows how to analyze a tuning fork based piezoelectric rate gyroscope. The direct piezoelectric effect is used to drive an in-plane tuning fork mode. This mode is coupled to an out of plane mode by the Coriolis force and the resulting out of plane motion is sensed by the reverse piezoelectric effect. The geometry of the tuning forks is designed so that the eigenfrequencies of the ...
Microresistor Beam
Microresistors allow for quick and accurate actuation or structural movement directly related to the electricity that is applied to them. Microresistors can be used in many applications where small perturbations or deflections are required to be applied to devices, almost instantaneously. The Microresistor Beam app illustrates the importance of fully coupled, multiphysics simulations. An ...
Gecko Foot
In nature, geckos use dry adhesion forces to climb walls. They have inspired researchers to develop synthetic gecko foot hairs to be used in, for example, robot applications. This model contains the nano/micro hierarchy of a synthetic gecko foot hair, where cantilever beams both in nano and micro scales describe the seta and spatula parts of one spatula stalk attached to a gecko foot. The ...
