Influence dans le procédé de hot embossing des propriétés rhéologiques des polymères amorphes

Le but de cette étude est de décrire l‘écoulement de polymères amorphes lors de leur compression à chaud afin d'évaluer les déformations et contraintes associées au procédé de hot embossing quelle que soit la topographie de surface à reproduire. Il a été vérifié dans un premier temps, que les matériaux sélectionnés possèdent dans les conditions expérimentales retenues (température et pression) des propriétés d'écoulement associées à leur indice de fluidité (MFI), de leur consistance (k), ainsi que de leur indice d'écoulement (n). Ces paramètres étant en préalable déterminés au moyen d'essais caractéristiques. Il est démontré en référence à un écoulement entre deux plateaux idéalement plans que le remplissage de cavités lors du procédé de hot embossing peut être qualifié par un paramètre de remplissage (α) dont la valeur est déterminée expérimentalement

High resolution injection molding using silicon mould

Injection molding is a mature manufacturing method used to mass produce cost-effectively parts for a variety of applications. The focus of this work is on using injection moulding to produce polymeric parts with micronic to sub-micronic features. A dry-etched silicon mould insert with ridges of width from 5µm to 300nm was fabricated using electron beam lithography and dry etching. Replicas were made in Polypropylene. Experiments as a function of injection temperature, applied pressure, and injected volume were conducted to optimize the filling of microcavities of the mould insert

"Synthèse de l'année 2007 - L'instrumentation pour la biologie", "Microfabrication ; Intégration "

"Microfabrication ; Intégration

Laser processing for bio-microfluidics applications (Part I)

This paper reviews applications of laser-based techniques to the fabrication of microfluidic devices for biochips and addresses some of the challenges associated with the manufacture of these devices. Special emphasis is placed on the use of lasers for the rapid prototyping and production of biochips in particular for applications in which silicon is not the preferred material base. Part I of this review addresses applications and devices using UV lasers for laser ablation and surface treatment of micro- channels, in particular in polymer

Direct patterning of quantum dots on structured PDMS surface

International audienceSemiconductor quantum dots are currently the most attractive research areas due to its variety of applications, especially in the field of life science. The present work deals with direct patterning of quantum dots (CdSe) using a modified hydrophobic–hydrophilic PDMS surface. The hydrophilic monomer was stamped on a hydrophobic PDMS to generate pattern of hydrophobic–hydrophilic PDMS surface. Fluorescent microscopy shows the selective deposition of quantum dots onto the hydrophobic PDMS surface

Fabrication of long-term hydrophilic surfaces of poly(dimethyl siloxane) using 2-hydroxy-ethyl methacrylate

International audienceIn the present work, 2-hydroxy-ethyl-methacrylate (HEMA) was used to modify surface of poly(dimethylsiloxane)(PDMS) elastomer. Fourier transform infrared spectroscopy (FTIR) and wetting angle measurements were used for the analysis of modified surface and hydrophilic stability of PDMS. Results of the surface reconstruction reveal that long-term hydrophilic surfaces of PDMS can be achieved by use of HEMA

Hydrophilization and hydrophobic recovery ofPDMS by oxygen plasma and chemical treatment—An SEM investigation

International audienceRapid prototyping of polydimethylsiloxane (PDMS) is frequently used to build microfluidic devices. PDMS is inherently hydrophobic; however, the surface can be temporarily rendered hydrophilic by exposing the surface to oxygen plasma. Hydrophilic microchannels are sometimes advantageous over hydrophobic microchannels due to increased cell adhesion or increase in electro osmotic flow (EOF) leading to ease of liquid filling in microchannels. However, the hydrophilic surface is unstable and that low molecular weight (LMW) chains diffuse from the bulk of the PDMS and cover up the thermodynamically unstable surface. This is one reason for the hydrophilic unstability of PDMS. Present study shows that not only chemistry of the creation of silanol groups on the surface, but also morphology of the film surface nanostructuring of PDMS plays an important role in hydrophilization of PDMS. Present paper tries to understand the mechanism of hydrophobic recovery taking into consideration physical and chemical parameters using SEM characterization

Surface modification of poly(dimethyl siloxane) and its aging study for its use in microfluidics.

International audienc

Applications of LIGA technology to precision manufacturing of high-aspect-ratio micro-components and -systems: A review

RevueInternational audienceThe by far leading technology for manufacturing MEMS devices is Si-micromachining with its various derivatives. However, many applications of microsystems have requirements on materials basis, geometry, aspect ratio, dimensions, shape, accuracy of microstructures, and number of parts that cannot be fulfilled easily by mainstream silicon-based micromachining technologies. LIGA, an alternative microfabrication process combining deep X-ray lithography, plating-through-mask and molding, enables the highly precise manufacture of high-aspect-ratio microstructures with large structural height ranging from hundreds to thousands of micrometers thick. These tall microstructures can be produced in a variety of materials with well-defined geometry and dimensions, very straight and smooth sidewalls, and tight tolerances. LIGA technology is also well suited for mass fabrication of parts, particularly in polymer. Many microsystems benefit from unique characteristics and advantages of the LIGA process in terms of product performance. The LIGA technology is briefly reviewed. The strengths of the manufacturing method and its main fields of application are emphasized with examples taken from various groups worldwide, especially in micromechanics and microoptics

The “Tour de France” of public financing for MNT

International audienceNew tools which were developed to implement the French programme in micro/nano sciences and technologies are briefly reviewed. These tools were designed to promote synergies between the various players of French R&D, reinforce public / private partnership, reach a critical mass and increase efficiency, visibility and attractiveness of the overall system from science and technology to innovation