Microelectromechanical Systems (MEMS) are intensivly studied since many years due to their high potential performances and their integration possibilities. In particular, electromechanical resonators realized at the CMOS level could allow the emergence of integrated multi-frequency architectures suitable for future multiband wireless communication devices that might require many reference frequencies to address multiple communication standards. This paper presents a new 3D multi-frequency MEMS resonator design based on Lamé；-mode plate resonators. Mechanisms and Finite Element Modeling (FEM) simulations are detailed. The Silicon on Nothing process (SoN) can be used to realize such 0-stress 3D structures.

This paper reports on the design, simulation and fabrication of tunable MEMS capacitors with fragmented metal (AlSi 4%) electrodes. We examine a rotational electro-thermal actuation. An analytic model of the rotational effect thermal actuator was established in order to show the periodicity of the capacitance when the angle increases. Evaluation of the impact of fringing fields on the capacitance has been carried out using finite element analysis (FEA). The MEMS capacitors were fabricated using metal surface micromachining with polyimide sacrificial layer. The maximum rotation, corresponding to a maximum angle of 7 degrees, was obtained near 1.2 V and 299 mA. The proposed capacitor has a practical tuning range of 30%. FEA has shown that this figure can be improved with design optimization. The MEMS architecture based on rotational effect and fragmented electrodes does not suffer from the pull in effect and offers a practical solution for future above-IC capacitors.

In this article； a new concept of microswitch is investigated with the objective to decrease the actuation voltage. It consists in a component with two kinds of actuation mechanisms: piezoelectric actuation and electrostatic actuation. The structures were realized with a technology compatible with CMOS technology. Aluminium nitride (AlN) was selected as piezoelectric material for its maturity and integration capabilities.

This paper presents the study of piezoelectric actuators. After the description of simulated actuators and simulation conditions； results will be discussed to define the best actuator design in terms of membrane displacement and compactness. The actuator behaviour under temperature variation is also checked.

After consistently progress in Micro-Electro-Mechanical (MEM) resonators, Silicon oscillators are finally being. commercialized for time and frequency control applications not requiring huge frequency accuracy. Indeed, they. offer size reduction, potentially low cost and CMOS integration. However, frequency shift because of manufacturing. mismatch is still one of the challenges to address high frequency accuracy applications. We propose a new frequency. compensation method consisting in filling compensation holes smartly localized onto microresonators. This method. enables to decrease the frequency dispersion over a full wafer of only few ppm, regarding to deviation of 1000ppm. (C) 2011 Published by Elsevier Ltd.

This paper presents for the first time the characterization of a smartphone-size haptic rendering system based on the friction modulation effect. According to previous work and finite element modeling, the homogeneous flexural modes are needed to get the haptic feedback effect. The device studied consists of a thin film AlN transducers deposited on an 110 x 65 mm(2) glass substrate. The transducer's localization on the glass plate allows a transparent central area of 90 x 49 mm(2). Electrical and mechanical parameters of the system are extracted from measurement. From this extraction, the electrical impedance matching reduced the applied voltage to 17.5 V-AC and the power consumption to 1.53 W at the resonance frequency of the vibrating system to reach the haptic rendering specification. Transient characterizations of the actuation highlight a delay under the dynamic tactile detection. The characterization of the AlN transducers used as sensors, including the noise rejection, the delay or the output charge amplitude allows detections with high accuracy of any variation due to external influences. Those specifications are the first step to a low-power-consumption feedback-looped system.