The integration of high-performance RE-TM (NdFeB and SmCo) hard magnetic. films into micro-electro-mechanical-systems (MEMS) requires their patterning at the micron scale. In this paper we report on the applicability of standard micro-fabrication steps (film deposition onto topographically patterned substrates, wet etching and planarization) to the patterning of 5-8 mu m thick RE-TM. films. While NdFeB comprehensively fills micron-scaled trenches in patterned substrates, SmCo deposits are characterized by poor. filling of the trench corners, which poses a problem for further processing by planarization. The magnetic hysteresis loops of both the NdFeB and SmCo patterned. films are comparable to those of non-patterned. films prepared under the same deposition/annealing conditions. A micron-scaled multipole magnetic. field pattern is directly produced by the unidirectional magnetization of the patterned. films. NdFeB and SmCo show similar behavior when wet etched in an amorphous state: etch rates of approximately 1.25 mu m/min and vertical side walls which may be attributed to a large lateral over-etch of typically 20 mm. Chemical-mechanical-planarization (CMP) produced material removal rates of 0.5-3 mu m/min for amorphous NdFeB. Ar ion etching of such. films followed by the deposition of a Ta layer prior to. film crystallization prevented degradation in magnetic properties compared to non-patterned. films. (C) 2008 Elsevier B. V. All rights reserved.

We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 mu m thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated.

Downsizing and compatibility with MEMS silicon foundries is an attractive path towards a large diffusion of photoacoustic trace gas sensors. As the photoacoustic signal scales inversely with the chamber volume, a trend to miniaturization has been followed by several teams. We review in this article the approach initiated several years ago in our laboratory. Three generations of components, namely a 40 mm(3) 3D-printed cell, a 3.7 mm(3) silicon cell, and a 2.3 mm(3) silicon cell with a built-in piezoresistive pressure sensor, have been designed. The models used take into account the viscous and thermal losses, which cannot be neglected for such small-sized resonators. The components have been fabricated either by additive manufacturing or microfabrication and characterized. Based on a compilation of experimental data, a similar sub-ppm limit of detection is demonstrated. All three versions of photoacoustic cells have their own domain of operation as each one has benefits and drawbacks, regarding fabrication, implementation, and ease of use.

The MEMS digital loudspeaker consists of a set of acoustic transducers, called speaklets, arranged in a matrix and which operate in a binary manner by emitting short pulses of sound pressure. Using the principle of additivity of pressures in the air, it is possible to reconstruct an audible sound. MEMS technology is particularly well suited to produce the large number of speaklets needed for sound reconstruction quality while maintaining a reasonable size. This paper presents for the first time the modeling, realization and characterizations of a piezoelectric digital loudspeaker based on MEMS technology. Static, dynamic and acoustic measurements are performed and match closely with theoretical results. (C) 2012 Elsevier Ltd....Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.

In this paper we present the development of a resonant asymmetric micro mirror. In particular, we prove the possibility of using an Electro Active Polymer as actuation material. The working principle of the micro mirror and the design retained is first presented. Then the technological realization is summarized. We obtain micro mirror demonstrators and the first characterization results are given. These first promising results open the way of low cost and low temperature process actuators for Micro Electro Mechanical Systems.