The concept of silicon fibre technology follows the aspiration of making whole computers recede into textile format, which can be used in a wearable or ambient environment. The integration of IC technology into fibre format is an important development for a wide range of emerging scientific applications from wearable vital sign health monitoring systems [1] to Ambient Intelligence Microsystems.
This concept is achieved by building a device in silicon on insulator (SOI) [2] material and undercutting the sacrificial SiO2 layer by a combination of isotropic and anisotropic etch processes, to leave a freestanding functional fibre. A demonstration of functionality based on this technology was produced in the form of a PN diode on a fibre [3]. After demonstrating the feasibility of the concept, subsequent active device circuits were designed and fabricated as a more complex demonstration of functionality.
One of the primary considerations involved with this technology is the interconnection of these flexible silicon structures to each other and to the outside environment. A novel interconnection protocol has been developed and a prototype demonstration of a flexible LED circuit has been fabricated.