CONDUCTIVE FIBRE

Particular examples of using polymer composites as screens are given in [14-16, 67-75], The present review does not touch the properties of the composite materials based on fabrics of conducting fibres due to the fact that manufacturing techniques for such materials are specific and differ greatly from the mixing processes considered above. However, these materials also have an application field, say, in contacts for calculator and computer keyboards [9] and even in small-power electric motor commutators as a partial substitute for copper [76, 77]. 

Jana, P.B., Mallick, A.K., and De, S.K., Electrically conductive rubber and plastic composites with carbon particles or conductive fibres, in Short Fiber-Polymer Composites, De, S.K. and White, J.R. (Eds.), Woodhead Publishing, Cambridge, 1996, Chapter 7. 

Cardiac muscle is similar to skeletal muscle, but is not under conscious control. These mono-nucleate cells are much smaller, but still show a striated pattern. The cells are in electrical contact through communicating gap junctions. These are important for the orderly spread of excitation through the heart. Spontaneous electrical depolarization of the specialized pacemaker cells together with conducting fibres activate the bulk of the ventricular muscle in the chamber walls, in each case through direct electrical contacts. 

Dall Acqua et al.45 reported the development of conductive fibres made by cellulose-based fibres embedded with polypyrrole. Several efforts with cotton, viscose, cupro and lyonell have followed. The conductivity is directly related to the amount of polypyrrole, oxidant ratio and fibre structure with significant differences between viscose and lyonell. Polymerisation occurs uniformly inside the fibre bulk, by producing a coherent composite polypyrrole/cellulose. The mechanical and physical properties of cellulose fibres were not significantly modified as they are the best available45. 

Conductive fibres obtained through chemical deposition of coatings... 

Electromagnetic interface shielding is the most common application. Conductive fibres braided into a shield or sock offer superior performance against electromagnetic interference, and they present the following advantages ... 

Compatibility, yams of conductive fibres are fully compatible with standard braiding equipment5. 

A final method is metallisation11 of fibres, which is most related to the technology described in this chapter. In this method, metal salts are taken up by the fibre and reduced to their metallic conductive form. Metallisation can be achieved in different ways. A first way is by a vacuum metal spray. However, this results in very poor defined metallisation. In addition, galvanic coating is used in the production of conductive fibres, but this type of coating requires a fibre that is already conductive. 

Fibres made from carbon-filled polyolefin or polyester have been added to battery paste to increase life [42]. In another approach [43], a battery plate was made by filling a non-conductive polyvinylchloride grid with paste and covering the plate with a sheet of partly carbonized, organic, non-conductive fibres. The carbonized layer on the fibres provided the electrical conductivity. 

One example of such smart textile applications is in health monitoring [50]. Placement of electrically conducting fibres in smart material clothing can be... 

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