Papers by Véronique Conédéra
Future adaptive optics (AO) systems require deformable mirrors with very challenging parameters, ... more Future adaptive optics (AO) systems require deformable mirrors with very challenging parameters, up to 250 000 actuators and inter-actuator spacing around 500 mum. MOEMS-based devices are promising for the development of a complete generation of new deformable mirrors. Our micro-deformable mirror (MDM) is based on an array of electrostatic actuators with attachments to a continuous mirror on top. The originality
2004 24th International Conference on Microelectronics (IEEE Cat. No.04TH8716), 2004
Absrrrrcr -This paper outlines the power capabilities of W MEMS devices. It is shown the specific... more Absrrrrcr -This paper outlines the power capabilities of W MEMS devices. It is shown the specific needs concerning the technology, the design and the geometry of the devices in order to circumvent self-actuation, AC electromigration, thermal effect and Reliability.
Proceedings of IEEE Sensors, 2004., 2004
This paper presents a MATLAB code which simulates the response of capacitive humidity sensors sub... more This paper presents a MATLAB code which simulates the response of capacitive humidity sensors subjected to humidity variations. The sensors have parallel electrodes and dielectric polymer-based sensitive coatings. User-defined parameters regard the geometry of the sensor, the physical chemistry of sorption in the sensitive film and the environment of the sensor. The code includes electrostatic and gas diffusion calculation. The
2005 European Conference on Power Electronics and Applications, 2005
This paper describes the fabrication steps of a spiral-type inductor designed for power electroni... more This paper describes the fabrication steps of a spiral-type inductor designed for power electronics conversion. Realized on silicon wafer and using photolithography and electroplating techniques, this microinductor is composed of a copper spiral conductor sandwiched between two iron-nickel laminated magnetic layers. Furthermore, specific devices have been realized in order to characterize the magnetic material
International Conference on Solid State Sensors and Actuators, 2003
A new microfluidic actuator for in situ oligonucleotides synthesis on DNA chips has been develope... more A new microfluidic actuator for in situ oligonucleotides synthesis on DNA chips has been developed. It consists in a microarray of individually addressable ejectors able to deliver pl droplets. The working principle is based on thermal ink-jet printing. The design of the micro injector has been deduced from FEM simulation, in order to achieve 4000 ejectors/cm2. The technological fabrication process
Sensors and Actuators A: Physical, 1998
This paper presents a new technological process to implement efficient millimetre-wave passive ci... more This paper presents a new technological process to implement efficient millimetre-wave passive circuits on a silicon substrate. This process associates a thick positive photoresist acting as a mould for the realization of thick conductors (several microns) with an ultra-thin dielectric membrane using only two layers (SiO2/Si2N3.8) in order to reduce both dielectric and ohmic losses in the coplanar millimetre-wave circuits.
18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005., 2005
RF microelectromechanical (MEMS) switches are usually limited in term of power handling. Self act... more RF microelectromechanical (MEMS) switches are usually limited in term of power handling. Self actuation and electro migration constitute indeed the main failure mechanisms related to medium and high RF power. To overcome these malfunctions, an original MEMS topology based on the use of two bridge levels is proposed in this paper. Both appropriate design and technology have been developed in
Sensors and Actuators B: Chemical, 2006
Love-wave devices gained enormous interest for sensor applications which need real time analyses ... more Love-wave devices gained enormous interest for sensor applications which need real time analyses and high sensitivity. These devices proved to be suitable for sensing physical quantities like mass. This effect is known as the main sensing mechanism in acoustic sensors and thanks to their high sensitivity, Love-wave can detect a small mass loading on the surface of the acoustic propagation
Sensors and Actuators A: Physical, 2010
The paper describes a new architecture of a Safe Arm and Fire device (SAF) that could constitute ... more The paper describes a new architecture of a Safe Arm and Fire device (SAF) that could constitute a real breakthrough for safe miniature fuzing device. On the one hand, it takes all the functions embodied in a conventional mechanical arm and fire system and integrates them in a single 1 cm 3 package made of assembly of different parts. On the other hand, for the first time, it combines a mechanical arming unit with electrical safety functionalities on the same silicon initiator's chip. It respects the STANAG 4187 norm (1 A/W during 5 min of not fire) and requires only 635 mW for ignition. The paper presents the design, fabrication and test of one miniature SAF device integrating a micropyrotechnical actuation.
Sensors and Actuators A: Physical, 2008
This paper exhibits a microfluidic solution to allow Love wave acoustic oscillators working under... more This paper exhibits a microfluidic solution to allow Love wave acoustic oscillators working under highly viscous liquid environments. Attenuation caused by viscous coupling is limited by using a poly(dimethylsiloxane) (PDMS) chip bonded on the Love wave device. Liquid volume required for a measurement is thus minimized to the microliter order. Thanks to insertion losses decrease, the non-Newtonian behavior of silicone oils up to 30 Pa s can be observed in oscillator mode. Numerical simulations based on the transfer matrix method have been performed to modelize the sensor response.
Sensors and Actuators A: Physical, 1995
We have studied the use of spin-on glass (SOG), as a sacrificial layer and source of dopant, for ... more We have studied the use of spin-on glass (SOG), as a sacrificial layer and source of dopant, for the realization of an electrostatic micromotor. Some difficulties have been encountered, and we propose a new process based on SOG, a classical POCl3 dopant source and oxidation of polysilicon to avoid these difficulties.
Microelectronic Engineering, 2004
We report a new approach to the correlation of the structural properties and the transport proper... more We report a new approach to the correlation of the structural properties and the transport properties of carbon nanotubes. Through an original combination of UV lithography, custom-made photosensitive sol–gel resist and deep reactive ion etching (RIE), we have successfully integrated membrane technology and nanodevice fabrication for the electrical connection of individual carbon nanotubes. After single wall nanotube (SWNT) deposition by
Journal of Power Sources, 2010
Carbon-based micro-supercapacitors dedicated to energy storage in self-powered modules were fabri... more Carbon-based micro-supercapacitors dedicated to energy storage in self-powered modules were fabricated with inkjet printing technology on silicon substrate. An ink was first prepared by mixing an activated carbon powder with a PTFE polymer binder in ethylene glycol stabilized with a surfactant then deposited by inkjet on patterned gold current collectors with the substrate heated at 140 • C in order to assure a good homogeneity.
Journal of Physics and Chemistry of Solids, 2010
We propose a safe, arm and fire (SAF) device that could constitute a real breakthrough for safe m... more We propose a safe, arm and fire (SAF) device that could constitute a real breakthrough for safe miniature fuzing device. It integrates all the functions of a conventional mechanical arm and fire system and integrates them within 1 cm 3 . For the first time, it combines a mechanical arming unit with electrical safety functionalities on the same silicon initiator's chip. It requires only 635 mW for ignition.
Journal of Micromechanics and Microengineering, 2007
The development reported herein is that of a surface micromachining technology using two SU-8 lay... more The development reported herein is that of a surface micromachining technology using two SU-8 layers as a structural material. Three different processes are presented and discussed: the first process makes use of a sol-gel as the sacrificial layer; the second process utilizes the SU-8 itself as the sacrificial layer; the third process utilizes silicon dioxide as the first sacrificial layer
Journal of Micromechanics and Microengineering, 2006
The fabrication of three-dimensional (3D) microfluidic networks entirely made of SU-8 with integr... more The fabrication of three-dimensional (3D) microfluidic networks entirely made of SU-8 with integrated electrodes is reported. The described technology allows the fabrication of uncrosslinked SU-8 dry film on a polyester (PET) sheet and its subsequent lamination to form closed microstructures. Unlike other reported methods, transferred layers are patterned following the bonding step allowing a more accurate and simple alignment between levels than techniques using already patterned layers. Dry release of the complete polymer microstructure was demonstrated. Flexible microfluidic chips were obtained. This technique uses simple tools and no wafer bonder is used but lamination techniques which are more collective processes. Limitations in the method for layers thicker than 50 µm have been observed and are discussed. Hydraulic flow experiments have been performed to study the deformation of the cover layer which could influence adjacent flow in a three-dimensional configuration. Important deformations have been observed for layers 10 µm thick and an average pressure greater than 100 kPa. No deformations have been noted for layers with thicknesses greater than 35 µm and for average pressures up to 200 kPa. No failures occurred within the range of the experimental set-up, i.e. up to 300 kPa.
Journal of Micromechanics and Microengineering, 2001
A new design of fluidic microdiode is proposed. An initial numerical simulation of this so-called... more A new design of fluidic microdiode is proposed. An initial numerical simulation of this so-called vortex microdiode allows us to understand the working principle of the diode. It is shown that the complex relationship between the inertial and viscous effects may lead to paradoxical results: as an example, an increase in the viscosity can involve an increase in the flow rate. The simulated performances, confirmed by experimental measurements with a microdiode etched by deep reactive ion etching on a silicon wafer, are compared to the performances of other microdiodes described in the literature. The efficiency of the vortex microdiode is found to be comparable to that of the Tesla microdiode, which was the most efficient microdiode. This is very encouraging, all the more so since the optimization perspectives are varied, due to a sophisticated design.
Journal of Micromechanics and Microengineering, 2012
This special issue presents devices and the results of a tunable microwave microsystem associatin... more This special issue presents devices and the results of a tunable microwave microsystem associating RF circuits and microfluidic components. A channel is buried inside the substrate of a microstrip waveguide. This channel is located beneath a resonant stub. With this configuration a microfluidic passive tunable filter can be fabricated. Dielectric fluids are used to disrupt the electric field in a microstrip structure and thus modify the effective permittivity of the substrate. In this work, a notch filter is realized with an open-ended quarter-wavelength stub placed on top of a hollow SU-8 structure. This structure offers two advantages: channels can easily be fabricated and a reduction of SU8 losses. The filter shows a good performance; the initial cut-off frequency of 25 GHz shifts more than 20% when deionized water is used in fluidic channels. And the shape of RF function is kept throughout the range.
Aerospace Energetic …, 2002
... of 65 s. The use of four piezoelectric microvalves to regulate gas flow enabled the reduction... more ... of 65 s. The use of four piezoelectric microvalves to regulate gas flow enabled the reduction of ... thruster is the low thrust-to-power ratio due to the high thermal conductivity of silicon. ... They have a better reliability than the liquid propulsion and can be also are used during the ...
Microelectronic Engineering, 2010
ABSTRACT This paper deals with the study of spin coating processes for the deposition of polysilo... more ABSTRACT This paper deals with the study of spin coating processes for the deposition of polysiloxane-based thin films. Specific developments are proposed in order to adapt the hydrodynamic laws theory to the spin coating of Maxwellian liquids. Theoretical and experimental results are compared, evidencing a good fit and enabling to define the Maxwellian law for the studied polysiloxane polymer. Finally, the theoretical developments are successfully extended to the BCB 4026 and SU-8 3050 photosensitive resins.
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Papers by Véronique Conédéra