Articles techniques et présentations

Excessive air damping can be detrimental to the performance of oscillating MEMS components. Complex systems, such as structures in pre-etched cavities or angular comb-drive scanning mirrors, typically require simulations to reliably evaluate the air damping. The simulated and ... En savoir plus

Nondestructive inspection (NDI) of damages (e.g., imperfect or degraded bonding lines) or the remaining strength of adhesively bonded lap joints is critical for the operational safety of aircrafts and vehicles. It remains a challenge to use the conventional NDI to quantitatively infer ... En savoir plus

A compression driver is a certain type of electrodynamic loudspeaker which has a phase plug with slits in front of the diaphragm. The slits are narrow enough that the so-called viscothermal effects are of significant importance. In this paper a 2D axisymmetric finite element model of a ... En savoir plus

Elastomeric elements are currently used as external dampers in many applications to increase the stability of dynamical systems, e.g., rotor-bearings systems. However, the dynamic design of systems embedded with elastomeric dampers is a hard task, since the properties of this kind of ... En savoir plus

Condenser microphones will have an electrical output for any displacement of the membrane relative to the back plate, which is usually bound to the microphone housing. For the typical use case, a pressure input will create a pressure difference across the membrane, which causes a ... En savoir plus

Figure 1 shows a simplified scheme of a typical industrial steam methane reforming (SMR) reactor, which is a top-fired, packed-bed multi-tubular chemical reactor, consisting of a series of catalytic tubes arranged within a furnace. The tubes contain two adjacent catalytic sections filled ... En savoir plus

RAKON is a worldwide expert in high performance crystal oscillator. The company decided to expand its product range to larger space equipment, the Master Reference Oscillator (MRO). This product is composed of stacked mechanical modules, joined together by structural screwed assemblies. ... En savoir plus

We present an easy-to-use toolbox for the automated generation of reduced-order mixed-level models for the evaluation of squeeze-film damping in microelectromechanical systems. The toolbox is programmed in JAVA and heavily exploits the functionality provided by the COMSOL API. The ... En savoir plus

In diatomic molecules, the anti-bonding eigenstate is the higher energy state as the chemical bond is weakened between the two atoms due to the destructive interference of electronic wavefunctions. It is counterintuitive for the anti-bonding state to have lower energy given the bonding ... En savoir plus

Electret condenser microphones are one of the most used transducers for a variety of applications. The engineer designing these cartridges must take into consideration many factors to create a design that meets its specifications. Most parts of the design have multiple constraints across ... En savoir plus