e-TAGs: e-Textile Attached Gadgets

The integration of wires and electronics into textiles (e-textiles) has many potential applications for wearable and pervasive computing. Textiles are an integral part of everyday life, from clothing we wear to the carpet we walk upon. Being able to combine electronics with textiles would enable pervasive computing to blend into the background so that the user can go about a normal routine. One of the challenges in e-textile implementation is connecting the electronic components to the fabric cheaply and reliably. This paper describes the design and implementation issues of e-TAGS (e-Textile Attached Gadgets). E-TAGs can use a variety of methods to connect to wires in an e-textile. This design allows for e-textile electronics modules that are easily attachable, removable, replaceable, and interchangeable. This paper presents the system architecture, connection techniques, communica- tion alternatives, and experiences from the construction of a prototype wearable e-textile with multiple e-TAGs. I. I NTRODUCTION The pervasive computing community envisions com- puting capabilities transparently available anytime, any- place, and anywhere. Such computing will interact seam- lessly with the user and the user's environment, pro- viding the user with the ability to act on and within the user's surroundings. Building this intelligent envi- ronment requires integrating computing, communication, and sensing capabilities into everyday items in a cost efficient and reliable fashion. Textiles are an intrinsic part of our environment, from the carpet on the floor to the chairs that we sit on, from the drapes over the window to the tapestry on the wall, from industrial uniforms to the latest fashionable clothing. Not only are textiles already part of our envi- ronment, they make an excellent platform for embedding and integrating computing, communication, and sensing capabilities in a durable, reliable fashion that integrates nearly invisibly into the user's environment. Such an approach can benefit from low-cost, high-volume textile manufacturing techniques, the large surface area of tex- tiles, and the intrinsic strength and flexibility of textiles. Textiles integrated with electronics, often called e- textiles, are traditional textiles augmented with electronic devices, communications, and power storage/generation capabilities. Although many components, including wires, fiber batteries, and some antennas can be woven or stitched directly into the fabric, other components such as discrete sensors and most chips need to be attached to the fabric. Post-weave attachments abound in the textiles industry, including buttons, snaps, rivets, ribbons, zippers, and rhinestones. In this paper, we consider the design issues associated with an e-textile architecture that incorporates small printed circuit boards (PCBs) that integrate computing devices, sensors, and actuators and communicate over an e-textile backplane. The term e-Textile Attached Gadgets, or e-TAGs, is given to these small electronic devices. This paper explores the following basic issues associated with designing such an architecture. • What factors limit physical e-TAG size? • What protocol should be used for communication between e-TAGs?