• PDF / 478,221 Bytes
• 6 Pages / 612 x 792 pts (letter) Page_size
• 34 Downloads / 282 Views

DOWNLOAD

REPORT

---

1271-JJ04-03

Stretchable and Washable Electronics for Embedding in Textiles Thomas Vervust1, Frederick Bossuyt1, Fabrice Axisa1, Jan Vanfleteren1 1 IMEC-UGent, Centre for Microsystems Technology (CMST), Technologiepark 914, Ghent, 9052, Belgium ABSTRACT Electronics in “wearable systems” or “smart textiles” are nowadays mainly realized on traditional interconnection substrates, like rigid Printed Circuit Boards (PCB) or mechanically flexible substrates. The electronic modules are detachable to allow cleaning and washing of the textile. In order to achieve a higher degree of integration and user comfort, IMEC-UGent/CMST developed a technology for flexible and stretchable electronic circuits. The electronic system is completely embedded in an elastomer material like PDMS (silicone), resulting in soft and stretchable electronic modules. The technology uses standard packaged components (IC’s) and meander shaped copper tracks, so that stretchable systems with complex functionality can be achieved. Testing methods for washability were selected and developed. First tests are showing promising results, leveling the path to washable electronics in textiles. In order to show the possibilities of the technology in the field of textile applications a 7x8 single color stretchable LED-matrix was designed and integrated in textile. This LED-matrix can be applied for example in wearable signage applications. INTRODUCTION In the current era of “ambient intelligence” the citizen carries along more and more electronic systems during all kinds of activities at all kinds of places. The limitation on user comfort and mobility of this increasing number of “portable” electronic systems must be kept to a minimum. Ideally these systems are quasi invisible and non-noticeable to the user. An obvious way to compile these portable electronic systems to one aggregate and to carry along the system in a comfortable way, is to integrate it in textile. A lack of technology for real integration of textile compatible electronics with high functionality is one of the factors which prevent a massive breakthrough of “intelligent textile” products at the moment. Therefore we developed a technology for flexible and stretchable electronics [1-2]. This technology is further extended in such a way that the soft and elastic electronic devices can be integrated into textiles and are washable. STRETCHABLE TECHNOLOGY The stretchable electronics technology uses standard SMD electronic components, typically being non-stretchable. They are grouped in non-stretchable functional islands which are interconnected by 2-D spring-shaped copper connections. This principle is shown in figure 1. The stretchable electronics technology is based on standard PCB manufacturing technologies. Lamination is used to create the base substrate. The flexible islands and copper meanders are defined by lithography and etching steps. SMD-components are soldered in a reflow oven. Molding techniques are used to encapsulate the electronics in an elastomer. This process is described elsewhere [3