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TEXTILE INDUSTRY - Inwoven intelligence

We are familiar with the concept of ‘intelligent’ machines. Now a new breed of ‘intelligent’ materials – which sometimes seem to belong more on the pages of a science fiction novel – is emerging. Research into these fabrics of the future is very real and increasing all the time.

Subtle textiles that warn in the event of medical symptoms are built into underclothes or other fabrics worn against the body. Developed by Philips Research.

These futuristic explorations aim to give textiles the capacity to perceive selected aspects of their environment, reacting, for example, to differences in temperature, electrical or magnetic fields, lighting conditions or ambient colours. Depending on the stimuli, they can adapt by changing shape, insulation power, colour or elasticity. In other words, they are able to correct a situation spontaneously. If necessary, they can provide cognitive functions, such as the recording and storage of data, or the sending or reception of signals. They can even operate as polyvalent intermediaries for remote information and communication. However fantastical this may seem, the fact is that the first concrete practical applications are already being realised.

Dealing with extreme conditions
Attempts are being made to develop a new generation of ‘reactive’ fibres or fabrics with a ‘sensorial electronic conductivity’ that incorporate flexible and imperceptible nanofibres (of nickel, copper, silver, etc.). This textile intelligence is clearly of great interest to the military, a field in which attempts are being made to develop clothing that reacts symbiotically with the environment and increases the sharpness of the senses. The armed services are also looking for garments that offer higher protection and the ability to communicate between personnel in the field.

Another very high-tech sector concerns continuous security monitoring on manned space flights as well as matters of ‘comfort’ for the crew (see box). This latter concern of course applies to all missions in extreme environmental conditions. Intelligent textiles developed for military or space applications can also be transferred rapidly to other high-risk civil uses such as operations in underwater or polar environments, combating fire or industrial disasters, or radioactive decontamination.

Beyond white coats

SEM view of a textile support with microcapsules.
© IFTH

This quest for intelligent textiles can also potentially generate a wide range of applications in many fields, such as sports and medicine. The interactivity between humans and textiles makes it possible to go beyond present technologies of localised skin sensors which are not very versatile.

Underwear is being studied, for example, that is able to react to changes in body rhythm indicating cardiovascular or diabetic irregularities. In this way, textiles could be used to monitor a person’s vital signs. Researchers at Philips have developed a bra made of a textile that can record data and emit a signal in the event of a cardiac problem.

For its part, Belgium’s Centexbel is studying the textile transposition of a known technology for the rehabilitation of paralysed limbs. This process is known as functional electrical therapy. It is based on the stimulation of certain motor functions through electrodes that transmit electrical microwaves. “The aim is to integrate this FET motor aid into a textile structure that would offer the patient a user comfort on a completely different level to present devices,” explains researcher Fabrice Pirotte. “For that, we are aiming to develop a sensorial fabric containing sufficient conducting fibres for the passage of microwaves.”

Trendy technology

Hollow synthetic fibres viewed under a scanning electron microscope (SEM).
© IFTH

These innovations have also attracted the interest of fashion designers. Prototypes have already been presented of garments based on fibres fitted with microcapsules able to release chemical reagents depending on temperature or light intensity, etc. A blue T-shirt that turns white when the sun comes out, summer dresses that exude a perfume that, when needed, can repel certain insects, are just two examples.

Fascinated by this marriage of fashion and technology, French designer Olivier Lapidus works regularly with research centres and has already registered a number of patents. In 1996, he presented an anorak with solar sensors and micro batteries that regulated the fabric temperature. In 2002, in association with Nokia and Sony, he designed a jacket with a built-in mobile phone whose screen and keyboard are concealed in the sleeves and speakers and microphone in the collar. Another designer, Elisabeth de Sennevile, is studying clothes able to filter out pollution and dust, following in the footsteps of the anti-perspiration, anti-bacteria, and even anti-stress textiles that are already a reality.

Ground control
In an entirely different niche market, the Bidim company, a specialist in unwoven(1) textiles used in construction, has developed a sophisticated system for detecting ground or subsoil movements that functions as a remarkably precise control and warning system. The process involves providing geotextile structures with polyester micro-sleeves containing what are known as ‘Bragg grating’ optical fibres. When a beam of light crosses the fibre, each network reflects a characteristic wavelength. Any ground deformation disturbs the ‘normal’ wavelength and millimetric variations can be measured to a precision of 0.01%.

(1) The term ‘unwoven’ designates textiles obtained from a direct mixing of fibres, without any spinning or weaving. Dispensing with these traditional stages in textile production, this particularly economic process is becoming increasingly widespread and the market for these products is growing rapidly for many technical uses that do not require an elaborate finish.

Baby astronauts

The sophisticated suits worn by astronauts are a remarkable source of inspiration for textile intelligence. The European Space Agency’s Spacelink programme – a proactive network promoting the transfer of space technologies to terrestrial applications – has developed three examples of particular significance.

The Mamagoose Babygro monitor heartbeat and respiratory arrests in babies likely to fall victim to cot death. © Verhaert

The Belgian company Verhaert Design & Development, in co-operation with the Université Libre de Bruxelles, has developed the Mamagoose Babygro. This garment monitors the heartbeat of babies during their sleep and gives the alert in the event of respiratory arrest. It provides a much more comfortable alternative to the various sensors placed under infants at risk of cot death.

For ‘children of the moon’, who suffer from a rare light sensitivity disorder (xeroderma pigmentosum) and cannot be exposed to ultraviolet rays, the ESA has developed anti-UV underclothes, as well as refrigerated transparent hats that could soon be commercially available.

Another application has been the subject of attention for a number of Spanish SMEs, under the leadership of the Zodiac company (which helped design the European spacesuit), as part of the Eureka project. By studying the thermal control systems of spacesuits, the partners came up with an underwear design that allows the body to retain a stable temperature in all circumstances. This application is of particular interest to fire fighters, the wearers of bullet-proof vests and also bakers and motorcyclists. In this case, it is not so much the textile as the technology built into the garment – a sophisticated system of air circulation and heat exchange – that create the optimal conditions.