Textile materials, natural or synthetic are predominantly insulators and as such do not allow for the flow of electricity through their structure, many possess dielectric properties, defined by their Dielectric Constant?. This inability to transport electrical current and the ability to generate trioelectricity allows electrical charges to remain static on the surface of materials. This static electricity and risk of Electro Static Discharge ?is problematic in textile processing and end use applications, the way of controlling this is through the introduction of conductive materials to transport and dissipate the charge.
Control of static electricity is not the only application of conductive materials in textiles. The emergence and growth of smart textiles has found applications such as the integration of sensors and electronic devices into textile products across a range of market sectors. Conductive textiles can transport electrical signals as well as electrical current, and as such can be used to transport or store data.
Textile integrated sensors can allow remote monitoring of vital biological signs such as heart rate, having applications in medical, military and sports sectors. This sensing functionality has further use in engineering, automotive, aerospace and geotextile structures to monitor temperatures or pressure loads, with actively smart systems then able to respond intelligently to this electrical signal. The fundamental components in any smart textile are sensors and actuators. Interconnections, power supply and control units are also needed to complete the system, all of which require conductivity and, if to produce a system fit for purpose ease of integration into a textile product.
Electrical current charged and stored in textiles has the potential to offer an alternative power source for battery operated technology, increasing efficiency and reducing battery weight.
As technology advances human beings are becoming increasingly exposed to Electro magnetic radiation? from sources such as radios, mobile phones, televisions, microwaves and X-rays. Exposure on a small level has not show to be a risk; however protection is required from prolonged or high level exposure. Electrical equipment is sensitive to Electromagnetic interference (EMI), where exposure may cause temporary malfunction or complete failure. A way of reducing this exposure is through the implementation of EMI shielding materials. Conductive materials weaken electromagnetic waves by Reflection, conductive materials in the form of textiles or garments offer lightweight and practical shielding solutions.
Perhaps the most controversial application of conductive textiles is that of Taser proof clothing, clothing of this nature acts like a Faraday cage to protect the wearer from the charge. There are concerns this may pose a hazard or become used by criminals.
The development of Conductive textiles is of importance across a range of applications and products, products which have the potential to revolutionise the way we live and interact with our environment. But two crucial hurdles – unobtrusiveness and reliability – impede widespread adoption of such clever clothes. This is why continual development is required, to meet the increasing needs with smarter, lighter and more efficient solutions.
The approaches taken to add conductivity to textiles varies greatly dependant upon application which will dictate use factors such as required voltage, strength, durability and ductility, etc.
Approaches can include:
- Using an inherently conductive material/polymer
- Coating with conductive materials
- Use of conductive materials as fibres, yarns or threads.
In clothing, comfort is a requirement so conductive yarns have to remain flexible and soft whilst maintaining their conductive function. Wires have been found to not provide a good comfort level and the metallic materials used can be brittle and fail following prolonged wear conditions. Therefore traditional textile materials which already exhibit the required qualities in terms of comfort are being modified in order to obtain conductive qualities. This can be in the form of a coating of conductive materials or, for synthetic fibres, the introduction of these materials at the fibre manufacture stage.
Anti-static treatments introduce conductive materials in order to dissipate the static build up; this is often applied as a finish.