The Newest Products for Your Newest Designs® tor, professor Christophe Bernard from INSERM exposed his successful use of ultra-flexible printed electrodes, only 4um thick, to study brain messaging functions at neurone level. Before using such electrodes, neuro-researchers used to rely on fixed metal probes going through the skull and then through the brain, but as the brain moves and scarification tissues form around the electrodes, the signal deteriorates in a matter of days or weeks. By using PDOT-based flexible electrodes, not only the endprobes can move with the brain (for an unaltered signal), but the bio-compatible organic material means there is no rejection and the neurones being probed can be relied upon for longer. What’s more, on these electrodes, Bernard’s team implemented a transistor in direct contact with the brain, enabling a signal preamplification gain of 20dB. The long term goal of his research would be to be able to record and decode brain information in order to establish a brain-machine interface. This would allow the electrodes’ wearer to send the commands to an intelligent assistant or to an exoskeleton. According to market research firm IDTechex, the emerging www.electronics-eetimes.com Electronic Engineering Times Europe April 2015 17 Go Widest_UK_93x77.indd 1 26/03/15 13:27 battle grounds for printed electronics will be stretchable electronic textiles and conductive 3D surfaces for large area applications. And beyond organic-based printed electronic devices, the 5èmes Rencontres de l’électronique imprimée was an opportunity for representatives from the more traditional printing and textile industries to share their ideas for a successful reconversion, adding electronic functionalities to their product portfolio. President of the ATEP (the French association of publishing and advertising engineers), Hervé Rouher sees the integration of printed electronics into the traditional printing industry as a way to bring more value and create new jobs in a sector that faces an unprecedented crisis. “Small and medium enterprises in this sector should embrace printed electronics to add sensory functions and turn their paper substrate into large-area active components” he said. Rouher would rather talk about functionalized printing rather than printed electronics, an expression he finds too narrow when you consider how versatile printing technology can be, on paper or other substrates. The most immediate markets for functionalized prints include luxury labelling and packaging, smart labelling for the food and medical sectors, and packaging in general. Philippe Guermonprez, Collective R&D manager for the French Institute of Textile and apparel (IFTH) shared a similar view, looking at functionalizing textiles with either through screen printing processes or weaving electronic components as specialized yarns. Though he mentioned that printing on textiles is a very different story, since the substrate is three-dimensional, porous, deformable and often stretchable. All this makes printing electronic components much more difficult, and as more sensors are being integrated into fitness or health-monitoring garments, connectivity remains a challenge. On several occasions, Guermonprez reminded us that wash cycles at 80ºC were the most dreaded pass or fail test for any fabric integrating electronic components, submitting all the material layers to both mechanical wear and moisture. The most promising market in this sector include entertainment (with interactive or light-emitting clothes), sports (with fitness monitoring), but also so-called geotextiles to monitor large structure deformations.
EETE APR 2015
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