Pull-in of an RF MEMS Switch
This model analyzes an RF MEMS switch consisting of a thin micromechanical bridge suspended over a dielectric layer. A DC voltage greater than the pull-in voltage is applied across the switch, causing the bridge to collapse onto the dielectric layer with a resulting increase in the capacitance of the device. A penalty based contact force is implemented to model the contact forces as the bridge ...
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 ...
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 ...
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.
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. ...
Radially Polarized Piezoelectric Transducer
This tutorial model shows how a user-defined coordinate system can be used to create any type of directional polarization of a piezoelectric material. Results are shown for the case of radial polarization of a piezoelectric disk. The piezoelectric material is PZT-5H. The example shows a static analysis. Visualization of the cylindrical coordinate system as well as the stress/strain in that ...
MEMS Pressure Sensor Drift Due to Hygroscopic Swelling
For their integration in microelectronic circuits, MEMS devices are bonded on printed circuit boards and connected with other devices. Then, the whole circuit is often covered with an epoxy mold compound (EMC) to protect the devices and their interconnects with the board. The epoxy polymers used for such applications are subject to moisture absorption and hygroscopic swelling, which can lead to ...
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.
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 ...
Piezoelectric Valve
Piezoelectric valves are frequently employed in medical and laboratory applications due to their fast response times and quiet operation. Their energy efficient operation, also dissipates little heat, which is often important for these applications. This model shows how to model a piezoelectric valve in COMSOL. The valve is actuated by a stacked piezoelectric actuator. A hyper-elastic seal is ...