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We demonstrate a new electrode gate based on graphene ink for complementary printed organic metal oxide semiconductor (CMOS) technology on flexible plastic substrates. The goal is to replace the standard silver electrode gate. Devices made with graphene were enhanced and showed a high field-effect mobility of 3 cm 2 V −1 s −1 for P-type and 0.9 cm 2 V −1 s −1 for the N-type semiconductors. The improvement is attributed to the increase of the electrical capacitance of the organic dielectric (CYTOP) due to the graphene layer. A seven-stage ring oscillator was made with high oscillation frequencies of 2.1 kHz at 40 V corresponding to a delay/gate value of 34 μs. These performances are promising for use of low cost printed electronic applications.

Organic Thin film Transistors (OTFT) have been widely investigated in these last years as potential candidate for the development of low cost, flexible and lightweight active-matrix backplanes for display applications. Indeed the organic semiconductors provide both promising electrical performances tunable by chemistry and the ability to be processed at low temperature with innovative printing technics on various large scale substrates. Thanks to the recent developments on both n-type and p-type solution-processed organic semiconductors, we have developed a printable organic CMOS technology compatible with flexible PEN substrates. By combining state of the art materials exhibiting mobility in the range of 1 cm2/V.s and silicon inspired compact modeling and simulation approach, we were able to design and fabricate circuit's building blocks that provide the switching, digital and analog functions required for the fabrication of printed systems on foil.

International audience; Printed organic electronic is believed to be one of the next major technological breakthroughs in the field of microelectronic. The use of high throughput standard graphic arts printing to process organic field-effect transistors (OFETs) opens promising perspectives for low cost, large area and flexible circuits. Nevertheless, these techniques are commonly known to produce relatively thick (>1 μm) layers and to require complex inks formulations composed of several additives. In this paper, we demonstrate that screen printing and gravure printing may be highly versatile and could be well appropriate to deposit organic semi-conducting layers. These fast “single step” processes combined with amorphous semi-conducting polymer give thin, uniform and reproducible layers. The performances of printed or spin-coated films are similar and lead to robust and reliable full printed transistors and logic functions. Moreover, the capability of screen printing and gravure to deposit small patterns of semiconductor is discussed. Lines and spaces down to 500 μm are reported without specific inks and tools optimizations.

International audience; Sorting and recovering specific live cells from samples containing less than a few thousand cells have become major hurdles in rare cell exploration such as stem cell research, cell therapy and cell based diagnostics. We describe here a new technology based on a microelectronic chip integrating an array of over 100,000 independent electrodes and sensors which allow individual and parallel single cell manipulation of up to 10,000 cells while maintaining viability and proliferation capabilities. Manipulation is carried out using dynamic dielectrophoretic traps controlled by an electronic interface. We also demonstrate the capabilities of the chip by sorting and recovering individual live fluorescent cells from an unlabeled population.

Microfluidic networks are patterned in a dry film resist (Ordyl SY300/550) that is sandwiched in between two substrates. The technique enables fabrication of complex biochips with active elements both in the bottom and the top substrate (hybrid chips). The resist can be double bonded at relatively low temperatures without the use of extra adhesives. A postbake transfers the resist into a rigid structure. The resist is qualified in terms of resolution, biocompatibility and fluidic sealing. Fabrication in both a fully equipped cleanroom setting as well as a minimally equipped laboratory is described. The technique is applied for dielectrophoresis-based cell separation systems and a fuel cell reaction chamber with micropillars. The dry film resist can be considered a cheap and fast alternative to SU-8.

During the last decade, world-wide developments in micro-fabrication technologies have led to numerous Lab-On-a-Chip (LOC) micro-systems covering a wide spectrum of biotechnological applications. Although early LOC developments were driven by glass and silicon micro-fabrication techniques, in recent years polymeric-based LOC have been intensively developed. Taking advantage of each material, a hybrid device associating an active silicon chip with a passive polymeric micro-part has been developed to produce an addressable Cell-chip for individual cell manipulation and sorting. The complete hybrid micro-fluidic device fabrication is described here, including polymer structuring, hermetical sealing, biocompatibility studies, and fluidic interconnections with the sample as well as detection aspects. The cell manipulation is based on dielectrophoresis, which allows cell motion without fluid flow. First biological results will be presented.

SU-8, negative-tone epoxy base, photoresist has a great potential for ultra-thick high aspect ratio structures in low cost micro-fabrication technologies. Commercial formulation of NanoTM SU-8 2075 is investigate, process limitations are discuss. Good layer uniformity (few %) for single layer up to 200 μm could be obtained in a covered RC8 (Suss-MicroTec) spin coater, but for ultra-thick microstructures it is also possible to cast on the wafer a volume controlled of resist up to 1.5 mm without barrier. Long baking times are necessary for a well process control. The layout of the photo-masks design and process parameters have great impact on residual stress effects and adhesion failures, especially for dense SU-8 patterns on metallic under layer deposited on silicon wafers. A specific treatment applied before the resist coating definitely solved this problem. Bio-fluidic applications of on-wafer direct prototyping (silicon, glass, plastics) are presented. An example will be given on prototyping dielectophorectic micro-cell manipulation component. The SU-8 fluidic structure is made by a self planarized multi-level process (application for 2,5 to 3D microstructures). Biotechnology applications of integrated micro-cells could be considered thanks to the SU-8 good resistance to PCR (Polymerase Chain Reaction). Future developments are focusing on the SU-8 capabilities for Deep Reactive Ion Etching of plastic and 3D shaping of microstructures using a process called : Multidirectional Inclined Exposure Lithography (MIEL).

The lab-on-a-chip approach has been increasingly present in biological research over the last ten years, high-throughput analyses being one of the promising utilization. The work presented here has consisted in developing an automated genotyping system based on a continuous flow analysis which integrates all the steps of the genotyping process (PCR, purification and sequencing). The genotyping device consists of a disposable hybrid silicon-plastic microfluidic chip, equipped with a permanent external, heating/cooling system, syringe-pumps based injection systems and on-line fluorescence detection. High throughput is obtained by performing the reaction in a continuous flow (1 reaction every 6min per channel) and in parallel (48 channels). We are presenting here the technical solutions developed to fabricate the hybrid silicon-plastic microfluidic device. It includes a polycarbonate substrate having 48 parallel grooves sealed by film lamination techniques to create the channels. Two different solutions for the sealing of the channels are compared in relation to their biocompatibility, fluidic behavior and fabrication process yield. Surface roughness of the surface of the channels is the key point of this step. Silicon fluidic chips are used for thermo-cycled reactions. A specific bonding technique has been developed to bond silicon chips onto the plastic part which ensures alignment and hermetic fluidic connexion. Surface coatings are studied to enhance the PCR biocompatibility and fluidic behavior of the two-phase liquid flow. We then demonstrate continuous operation over more than 20 hours of the component and validate PCR protocol on microliter samples in a continuous flow reaction.