Micropositioning and Fast Transport Using a Contactless Micro-Conveyor

International audienceThe micro-conveyor is a 9 x 9 mm2 manipulation surface able to move millimeter-sized planar objects in the four cardinal directions using air flows. Thanks to a specific design, the air flow comes through a network of micro-channels connected to an array of micro-nozzles. Thus, the micro-conveyor generates an array of tilted air jets that lifts and moves the object in the required direction. In this paper, we characterize the device for transport and positioning tasks and evaluate its performances in terms of speed, resolution and repeatability. We show that the micro-conveyor is able to move the object with a speed up to 137 mm* s-1 in less than 100 ms whereas the positioning repeatability is around 17.7 µm with feedback control. The smallest step the object can do is 0.3 µm (positioning resolution). Moreover, we estimated thanks to a dynamic model that the speed could reach 456 mm* s-1 if several micro-conveyors were used to form a conveying line

Modélisation de la propagation des fissures courtes en fatigue dans le cas du 316L

L’expérience a démontré que la fissure fatale n’est pas nécessairement la plus grande relevée à un moment donné de la fatigue d’un matériau et qu’elle peut être la résultante d’autres microfissures. Ainsi, le dommage (par fatigue) est souvent associé au développement et à la croissance de microfissures en surface. L’avantage de considérer une population de fissures comme facteur physique d’endommagement est que les longueurs de fissures et leur nombre sont des données quantifiables qui peuvent être mesurées en surface du matériau. La présente étude est conduite dans ce sens et vise à caractériser l’endommagement et son évolution par la mesure de la densité de fissures en surface. Un modèle numérique, basé sur des principes aléatoires de génération de fissures, de leur propagation et de leur interaction mutuelle, est proposé. Il est ensuite appliqué dans le cas du 316L à température ambiante et pour des déformations plastiques égales à 8 × 10-3, 4 × 10-3 et 8 × 10-4

Parameter identification of PMSM using EKF with temperature variation tracking in automotive application

International audiencePermanent magnet synchronous machine is widely used for electric vehicles traction because of its high power density and its efficiency on a large flux weakening range. This paper focuses in particular on the estimation of PMSM parameters using EKF, we present a study assessing the temperature variations impact on the behavior of PMSM motor, and therefore we propose to estimate the temperature-dependent parameters. The main contribution in this work is an effective method for estimating parameters or their temperature variation, makes it possible to study and to avoid performance degradation by tracking and adapting the parameters in torque observer in order to find the same performance at any temperature and can be also used for thermal monitoring, which allows for better availability of motor, without causing damage, however, the knowledge of degradation mechanisms also gives insight for the design of this machine. Nowadays, there are essentially maps of reference currents according to the torque and speed that are used by car manufacturers and no account is then given of the parameter variations. The effectiveness of the proposed estimation method verified by both simulation and experiment

Acoustic mixer using low frequency vibration for biological andchemical applications

International audienceLiquid mixing at micro-scale is considered a challenge which is even tougher to overcome in the caseof discrete microfluidic. Many researchers have developed strategies and tried to be pioneer in mixingsolutions for lab on chip. In this paper, we present a parallel microdroplet mixer based on acoustic fieldgeneration using a low frequency vibration (up to few hundreds of kilohertz). This device can be usedfor lab on chip applications, since the liquid characteristics are not disturbed by the plugged energy andinvolve relatively simple microfabrication techniques. We designed, fabricated, evaluated, presentedexperiments showing the microdroplet active mixing, and investigated the thermal effect of the createdacoustic energy

Magnetic field effect on nonlocal resonance frequencies of structure-based filter with periodic square holes network

International audienceIn this paper, we investigate the magnetic field, thermal loads and small scale effects on the dynamics vibration of a nanobeam structure composed of a rectangular configuration perforated with periodic square holes network and subjected to axial magnetic field based on Euler–Bernoulli beam model (EBM) and Timoshenko beam model (TBM). The developed resonance frequencies expressions are derived by modifying the standard equations of dynamics beam vibration. The small scale effect is adopted via the Eringen's nonlocal theory while the coupled governing equations are obtained and solved using analytical solution method in order to determine the resonance frequency of perforated nanobeam. It is found that the resonance frequency change, the magnetic field intensity, the thermal loads and small scale effects are in dependence with geometrical parameters such as size and number of holes. Therefore, these results are discussed for the investigation of the structure dynamic deformation and compared with literature results where new remarks are deduced and presented with detail for a proper design of M/NEMS structures

Analytical modeling for the determination of nonlocal resonance frequencies of perforated nanobeams subjected to temperature-induced loads

International audienceThis paper is concerned with the investigation of thermal loads and small scale effects on free dynamics vibration of slender simply-supported nanobeams perforated with periodic square holes network and subjected to temperature-induced loads. The Euler–Bernoulli beam model (EBM) and shear beam model (SBM) developed for the determination of resonance frequency are derived by modifying the standard Timoshenko beam equations. The small scale effect is included by using the Eringen's nonlocal elasticity theory while the thermal loads effect is included by considering the additional axial thermal force in the standard differential equations. Numerical results are shown that the resonance frequency change, the thermal loads and the small scale effects are depended on size and number of holes. Thus, numerical results are discussed in detail for a properly investigation of the dynamic behavior of perforated nanobeams which are of interest in the development of resonant devices integrated in micro/nanoelectromichanical systems (M(N)EMS)

Le Traitement D'image Dans Les Mems : Outil Essentiel Dans La Caractérisation Sans Contacts Des Microsystèmes

International audienceLe Traitement D'image Dans Les Mems : Outil Essentiel Dans La Caractérisation Sans Contacts Des Microsystème

PADDIAG: Plasmon-Acoustic Device for in vitro Diagnosis

POSTER - Séminaire annuel du Labex ACTION 6 decembre 2013, BesançonThe aim of the project is to develop a plasmon-acoustic device for the real time detection of biomolecular interactions, in the prospect of cancer markers detection in blood samples from patients. In the context of early diagnosis, the detection of infinitesimal quantities of biomarkers is possible thanks to the breakdown of the equilibrium state of biochemical reactions. This could be obtained by the activation of the biological media using a system composed of a microdevice for generating acoustic waves coupled with a fluidic network. The latter system will be integrated on a detection device based on surface plasmon resonance. Here, we present design, realization and characterization of the acoustic activation device fabricated on silicon thanks to technological facilities of MIMENTO and ARCEN platform

Power Efficient Analog to Digital Conversion for the Li-ion Battery Voltage Monitoring and Measurement

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Mathematical model for the adsorption-induced nonlocal frequency shift in adatoms-nanobeam system

International audiencehis paper models and investigates the resonance frequency shift induced by the adsorption phenomena for an adatoms-nanobeam system including the small scale effect as well as rotary inertia and shear distortion effects. The Lennard-Jones (6–12) type potential is used to determine the adsorption-induced energy owing van der Waals (vdW) interaction mechanism between adatom-adatom and adatom-substrate. The small scale effect is introduced by using Eringen's nonlocal elasticity theory while the explicit expressions of inertia moment and shear force are derived from the standard Timoshenko beam equations in which the residual stress effect is accounted as an additive axial load. Numerical results showed that the resonance frequency shift is depended on each of the adsorption density, mode number and small scale effects. Thus, numerical results are discussed in detail for a proper analysis of dynamic vibration behavior of adatoms-nanobeam systems which are of interest in the development of mass sensing devices