Smart textiles and special engineered fibres

Many engineered polymer fibres are made today to meet different applications and requirements. Splitable microfibers are only one example and the splitting can be achieved chemically by alkali dissolution. Such fibres are used in high class apparel or to produce soft artificial leathers (sea-island fibres produced by Kolon Industries in Korea and Kararay in Japan).Other wet spun fibres such as viscose rayon can have phase changing material (PCM) incorporated into the spinning dope in the form of microcapsules. These feel cool to wear because heat from the body is readily absorbed by the microcapsules. They are also used in latent heat storage in buildings. The fibre marketed as Outlast is an example. Anitbacterial agents can also be added to reduce odours and silver is increasingly being used and is commonly found in some wound dressings. Special hollow filter fibres and membranes are used for gas separation and in renal dialysis can be made from polyacrylonitrile (PAN),polysulfone (PES) or polyvinylidene fluoride (PVDF). Winged fibres are an example where the outer sheath of a bicomponent fibre could be made of polylactic acid (PLA) which is water soluble leaving a insoluble core fibre (Allaso Industries). So called breathable fabrics made from stretched PTFE allow the passage of water molecules through them and Goretex clothing is an example. Early forms of conductive fibres used carbon to reduce static (anti-static fibres sometimes found in carpets) but are now being engineered with a conductive inner core and dielectric outer shear for bio-sensing Smart textiles with applications in robotics. Many different engineered structures are possible. High temperature applications use ceramic fibres whilst glass and quartz fibres are used in photonic applications for optical fibre data transmission.These can be made of stacks of hollow thin walled capillary tubes which are drawn down many times and coated with a sheath of suitable refractive index. Different types of glass can be used in solid fibres to create graded refractive index fibres. Nanofibres from carbon or silicon are also increasingly finding niche high tech applications and piezoelectric fibres can be used in sensor textiles.