Limoges, France
Limoges, France

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Rammal R.,University of Limoges | Delhote N.,University of Limoges | Tantot O.,University of Limoges | Verdeyme S.,University of Limoges | And 6 more authors.
Mediterranean Microwave Symposium | Year: 2013

In this paper, we report the printing of multilayered structures mixing silver nanoparticles and low temperature fired ceramics based inks. The conductivity of the silver ink is characterized up to 20GHz and above, and the typical performances of the technology and used dielectric material are given. A metallo-dielectric printed capacitance is finally presented as a first demonstrator. © 2013 IEEE.


Rammal R.,University of Limoges | Delhote N.,University of Limoges | Tantot O.,University of Limoges | Verdeyme S.,University of Limoges | And 5 more authors.
European Microwave Week 2013, EuMW 2013 - Conference Proceedings; EuMC 2013: 43rd European Microwave Conference | Year: 2013

In this paper, we report the printing of multilayer- structures mixing silver nanoparticles and low temperature fired ceramics based inks. The conductivity of the silver ink is characterized up to 20GHz and above, and the typical performances of the technology and used dielectric material are given. A metallo- dielectric printed capacitor is finally presented as a first demonstrator. © 2013 European Microwave Association.


Kanso A.,University of Limoges | Arnaud E.,University of Limoges | Monediere T.,University of Limoges | Thevenot M.,University of Limoges | And 3 more authors.
2012 15th International Symposium on Antenna Technology and Applied Electromagnetics, ANTEM 2012 | Year: 2012

In this paper, a novel Coplanar Wire-Patch (CWP) antenna for 2.5 GHz applications is presented. This antenna has been fabricated using inkjet-printing technology on a flexible, low-cost paper substrate using a simple, fast and cheap process compared to the photolithography technology. The design characteristics of the antenna are verified and the experimental measurements are successfully compared to the simulated ones. © 2012 IEEE.


Beaudrouet E.,Limoges National Superior School of Industrial Ceramics | Vivet A.,Limoges National Superior School of Industrial Ceramics | Lejeune M.,Limoges National Superior School of Industrial Ceramics | Santerne C.,Limoges National Superior School of Industrial Ceramics | And 4 more authors.
Journal of the American Ceramic Society | Year: 2014

BaTiO3-based materials are currently used for the fabrication of multilayer ceramic capacitors (MLCC) because of their high dielectric properties. The inkjet printing (IJP) process can be used to fabricate MLCC of complex configurations by integrating internal electrodes and dielectric layers in a single step using a multi printing-head system. Stabilized aqueous suspensions of BaTiO3-based powders are required to obtain dielectric inks adapted to IJP. This study investigates the influence of BaTiO3 powder hydrolysis in water on the surface chemistry and stability in relationship with the milling step used to adjust the powder grain size to IJP. Optimum parameters for a good stability of BaTiO3 suspensions are identified. The selected dispersant is a polyacrylate (PAA) for which the content is adjusted to minimize the sedimentation rates as required by IJP. Moreover, the addition of ethylene glycol is shown to be necessary to avoid the formation of a gel structure which could result from the interaction of borates ions leached from the surface of BaTiO3 with the PAA dispersant. A mechanism of gel formation is proposed. © 2014 The American Ceramic Society.


Bienia M.,Limoges National Superior School of Industrial Ceramics | Lejeune M.,Limoges National Superior School of Industrial Ceramics | Chambon M.,Limoges National Superior School of Industrial Ceramics | Baco-Carles V.,University Paul Sabatier | And 3 more authors.
Chemical Engineering Science | Year: 2016

Filament growth and breakup are investigated in the context of ceramic inkjet printing. Several inks were formulated and ejected on a printer dedicated to ceramic materials. They consisted of six colloidal inks, four simple fluids and two graphic inks. For each, stroboscopic snapshots were acquired and the filament shape was extracted and analysed, for different nozzle actuation pulses. The filament length and the thread minimum radius were measured during the ejection process. A scaling of the breakup time with the Rayleigh number was obtained, as well as a general behaviour for the filament growth rate during the ejection process. © 2016 Elsevier Ltd.


Singlard M.,Limoges National Superior School of Industrial Ceramics | Aimable A.,Limoges National Superior School of Industrial Ceramics | Lejeune M.,Limoges National Superior School of Industrial Ceramics | Dossou-Yovo C.,Ceradrop | And 3 more authors.
Powder Technology | Year: 2014

Ink-jet printing (IJP) is a rapid prototyping method which is very promising for the manufacturing of multilayer hybrid circuits. Before the formulation of inks, the first step aims to ensure the stability of dielectric powder suspensions with the specifications required for the IJP process in terms of solid content, particle size, rheology, and stability versus sedimentation. A commercial glass silicate powder currently used as a dielectric material was studied during an attrition milling (i) for low ceramic loading (3. vol.%) and (ii) for significant ceramic loading (20. vol.%) with different dispersants: polyelectrolytes with carboxylate groups, and sulfate groups. The milling step impact on the surface chemistry of the powder was investigated in both cases. A potassium polycarboxylate was found to be the most efficient dispersant, and the optimization of the dispersant rate was carried out through zeta potential measurements, viscosity, dispersant adsorbed rate, and sedimentation tests. An attempt of correlation between some of these properties is proposed. The preliminary ejection tests obtained with an ink prepared from an optimized suspension allowed to generate a wide range of drop velocity (0.7 to 4.2. m/s) and drop diameter (47 to 56. μm), which will be useful in a further step to optimize the characteristics of green ink-jet printed dielectric layers. © 2014 Elsevier B.V.


Nguyen L.,French National Center for Scientific Research | Maitre A.,French National Center for Scientific Research | Lejeune M.,French National Center for Scientific Research | Dossou-Yovo C.,Ceradrop | And 2 more authors.
Ceramics International | Year: 2013

The low temperature sintering of silica is studied under the influence of sintering aids and nanosized powders using X-Ray Diffractometry (XRD) and high-temperature environmental scanning electron microscopy analyses (HT-ESEM). Two particular aids were chosen to conduct this study, [Bi2O 3-ZnO]eutectic and titania. We report a lowering of the crystallization temperature when the former compound is introduced in the silica while a raise is observed when the latter is used. Moreover, the amorphous silica crystallization into cristobalite inhibits drastically the kinetics of densification of silica-based materials. © 2013 Elsevier Ltd and Techna Group S.r.l.


Arnaud E.,French National Center for Scientific Research | Kanso A.,French National Center for Scientific Research | Monediere T.,French National Center for Scientific Research | Passerieux D.,French National Center for Scientific Research | And 4 more authors.
Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012 | Year: 2012

This paper presents a solution to bypass the cost and flatness problems of electromagnetic band gap antennas. More precisely, a process to design an electromagnetic band gap antenna using frequency selective surfaces will be detailed. This kind of antenna had been designed before, but the used substrate is expensive and thin. A low cost and thick substrate (Plexiglas and window glass) has been used here, on which are printed the frequency selective surfaces using an inkjet printer; a cheaper process than photolithography technology. This type of substrate can also be used to manufacture the antenna radome. Finally, to validate this new structure, a 20 dBi antenna working around 7.5 GHz has been conceived, fabricated and successfully measured. © 2012 IEEE.


Kanso A.,XLIM OSA | Arnaud E.,XLIM OSA | Chreim H.,XLIM OSA | Monediere T.,XLIM OSA | And 4 more authors.
Microwave and Optical Technology Letters | Year: 2013

This article presents a solution to bypass the cost and flatness problems for low-cost electronic devices which is the inkjet printing. This process allows the use of flexible substrate materials, such as paper or plastics, suitable for a real-to-real process. More precisely, the procedure to design an electromagnetic band gap antenna using frequency selective surfaces and coplanar wire-patch antenna for 2.5-GHz applications is detailed. This kind of antenna has been designed before, but the used substrate is expensive and thin. These antennas were fabricated using inkjet printing technology on a flexible, low-cost paper substrate using a simple, fast, and cheap process compared to the photolithography technology. The design characteristics of the antennas were verified and the experimental measurements were successfully compared to the simulated ones. © 2013 Wiley Periodicals, Inc.


Senghora M.,DTS | Manceau M.,DTS | Ardiaca F.,DTS | De Bettignies R.,DTS | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

Inkjet printing is considered a promising technique for industrial production of Organic Photovoltaic (OPV) devices, especially due to its minimal consumption of materials, the easy modification of the numerical design and because this is a non-contact process. The objective of this study is to make efficient modules at a semi-industrial scale using 128 nozzle heads. In order to maximize the performance and lifetime, an inverted device structure was used consisting of: transparent plastic conductive substrate / N-layer / active layer / P-layer / silver electrode. Formulations and processes were therefore developed for substituting each spin-coated layer with an ink-jet printed layer. For 3.7 cm2 cells power conversion efficiency (PCE) reaches 3.3 % with only N-layer printed, 2.4 % with only active layer printed, 3.0 % with only P-layer printed and 2.9 % with only the silver electrode printed. Three-cell modules of 11 cm2 on 5x5 cm2 substrates were also made. Most PCE reach >2 % for each inkjet printed layer. © 2012 SPIE.

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