E-textiles, also known as electronic textiles, are fabrics that can function electrically as electronics and behave physically as textiles which enable computing ,digital components and electronics to be embedded in them. Part of the development of wearable technology, they are referred to as intelligent clothing or smart clothing that allow for the incorporation of built-in technological elements in everyday textiles and clothes. It does not strictly encompass wearable computing because emphasis is placed on the technology not being visible on the fabric and a computer is not actually embedded into the fabric. While not part of the mainstream form of fashion, its popularity is increasing and more research is being devoted to it.

The field of e-textiles can be divided into two main categories:

1) The first category involves mounting classical electronic devices such as conducting wires, ICs, LEDs and conventional batteries into garments.

2) The second category involves creating electronic function directly on the textile fibers. These functions can either be passive such as pure wires, conducting textile fibers, or more advanced functions such as transistors, diodes and solar cells. The field of embedding advanced electronic components onto textile fibers is sometimes referred to as fibertronics.

The most common approach to e-textiles today comprise the first category, which is technically the most simple approach, and where even a number of commercial products exists such as textiles with incorporated LED components.

There are also a number of research and commercial projects that comprise the use of hybrid structures between category 1 and 2. Here usually a less advanced electronic functions that is embedded into the textile fiber is connected to a classical electronic device or component. Some examples are touch buttons that are constructed completely in textile forms by using conducting textile weaves, and then connected to devices such as music players , or LEDs that are mounted on woven conducting fiber networks to form displays.

Construction of electronic function on textile fibers requires the use of conducting and semi-conducting materials. There are a number of commercial fibers today that include metallic fibers mixed with textile fibers to form conducting fibers that can be woven or sewn. However as both metals and classical semiconductors (such as Si) are stiff material they are not very suitable for textile fiber applications where fibers are subjected to large stretch and bending during use.

Another class of electronic materials which is more suitable for e-textiles is the class of organic electronics materials, (also referred to as conducting plastics, or inherently conducting polymers). As organic electronic materials can be both conducting, semiconducting and designed as inks and plastics, they are more suitable for making electronic fibers.

Some of the most advanced functions that have been demonstrated in the lab to date include:

– organic fiber transistors , this is the first textile fiber transistor that is completely compatible with textile manufacturing and that contains no metals at all.

– Organic solar cell on fibers .

2. BENEFITS OF E TEXTILES

Electronic textiles, or e-textiles, are a new emerging inter disciplinary field of research, bringing together specialists in information technology, microsystems , materials, and textiles. E textiltes offers the following advantages:

– Flexible

– No wires to snag environment

– Large surface area for sensing

– Invisible to others

– Cheap manufacturing

The focus of this new area is on developing the enabling technologies and fabrication techniques for the economical manufacture of large-area, flexible, conformable information systems that are expected to have unique applications for both the consumer electronics and aerospace/military industries.

PROPERTIES OF E – TEXTILES

Electrical properties:

From the electrical points of view, conductivity is the most important factor. Electrical resistance low enough to allow a flow of electric energy, such as for power or data transmission, is critical. Metal, carbon, or optical fibers are typically well-known conductors.

Conductive yarns are either pure metal yarns or composites of metals and textiles. Metals are superior in strength and fineness, and textiles are selected for comfort. In order to produce a successful conductive yarn, the best mix of conductive and non-conductive materials is critical.

As a thread takes on a bigger portion of conductive components, it loses the typical textile properties such as flexibility or drapability and becomes more conductive. The achievement in electrical resistance has ranged from 0.2441 ohms per meter (Ω/m) to 5,000 Ω/m.