smart textiles

Dr .Neelima GAssistant Professor, Dept. Of

Home Science

INTRODUCTIONTextiles are considered as the second skin of

humansProtection and aesthetics are two common

dimensions associated with textilesThird dimension—intelligence is being

integrated into fabrics to produce interactive textiles

Last few decades have shown enormous growth in the development of wireless communication, nanoengineering ,information technologies and miniaturization of electronic devices.

INTRODUCTIONThe world is distinctly rising towards the era of

smart and intelligent textilesThis new class of smart and intelligent textiles

is being designed to meet new and innovative applications in the

Military/DefenceMedical/health carespace explorationsportsFashion and entertainment

DefinitionSmart textiles are materials and structures

of textiles which can sense and react via an active control mechanism to environmental conditions called stimuli .They are capable of showing significant changes in their mechanical, thermal, chemical, optical or electromagnetic properties in response to the stimuli.

Classification Of Smart Fibres

§ Passive smart fibres, which can only sense the environmental condition or stimuli. Wearable sensors fall in this category viz built-in GPS,clothing integrated baby breathing monitors and clothing that gives potential changes about weather.

§ Active smart fibres, when clothing not only senses the environment but also reacts to the condition or stimuli. Examples include clothing that changes density depending on the temperature outside, jackets that store solar energy that can be used to charge cell phones.

Classification Of Smart Fibres

§ Active Very smart fibres, which can sense, react and adapt themselves accordingly .Example : space suit which can sense the outside temperature and adapt accordingly.

§ Ultra smart/Intelligent textiles, which are those capable of responding or activated to perform a function in a manual or pre-programmed manner.For example shirts that can store information through a built-in fabric keyboard and send it via bluetooth to a computer.

Smart materials usedThermo regulating materialChromic materialsLuminescent materialsConductive materialVoltaic materialsShape memory materialsMembranes materials

Thermo regulating material

PCMs are applied either in spinning or during chemical finishing of textiles like coating, lamination etc.

Paraffin phase change material(PCM) Goal is to maintain the core body

temperature and comfort of the wearer in diverse environments.

Provide a thermal balance between the heat generated by the body while engaging in a sport and the heat released into the environment.

Chromic MaterialsChange their colour reversibly according

to external environmental conditions ,hence also called chameleon fibres.

Photochromic: external stimulus is light. Thermochromic: external stimulus is

heat. Electrochromic: external stimulus is

electricity. Piezorochromic: external stimulus is

pressure. Solvatechromic: external stimulus is

liquid or gas.

Luminescent MaterialsEmits lights according to external

environmental conditionsPhotoluminescence: external

stimulus is lightElectroluminescence: external

stimulus is electricityChemioluminescence: external

stimulus is a chemical reactionTriboluminescence: external

stimulus is friction

Glow in the Dark textiles

Conductive materialsFunction: It conducts electricity.Properties: Light weight,

flexible, cost competitive with ability to be crimped, soldered and subjected to textile processing.

Preparation: It can be made by filling synthetic fibres with carbon,nickel,gold ,silver or metal particles, coating fibres with conductive polymers or using conductive short fibres.

Voltaic materials

Photovoltaic materials possess the property to generate electric current by means of a light excitation.

Solar cell fabric is embedded with photo voltaic cells (PV)

Capable of collecting more of sun’s energy from different angles than a flat stationery panel.

Solar fibres can not only charge our smartphones and gadgets but become wearable power sources for soldiers.

Shape memory materialAre polymeric smart

materials that have the ability to return from a deformed state (temporary)to their original(permanent)shape induced by an external stimulus(trigger)such as temperature change.

Membrane materials

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Membranes are deposited on textiles in order to add new properties onto their surfaces

Used in sportswear for the manufacture of breathable and impermeable clothes

Polymers used are polyfluorocarbon or polyurethanes.

Lotus effect provides repellence of the aqueous products and also of the oleic product resulting in ultra hydrophobic finishing – useful for self cleaning garments

Smart Fabric End Use

Musical Jacket

The musical jacket was first developed in 1997. It has a touch sensitive MIDI keyboard embroidered directly into the fabric using conductive thread.It contains stainless steel filaments, which makes it conductive.

Sound is generated by a single-chip General MIDI wavetable synthesizer, and sequences are generated in a microcontroller.

Musical Jacket

The jacket is entirely battery operated, with powered speakers in the pockets.

Wi-Fi detector t-shirt

A shirt with a built-in Wi-Fi signal detector

Glowing animated shirt dynamically displays the current Wi-Fi signal strength

Animated Decal is Removable (with hook and loop fasteners) for Easy Washing

Battery Pack is Concealed in a Small Pocket Sewn Inside the Shirt

Wi-Fi detector t-shirt

Space-suit

A space suit is a garment worn to keep a human alive in the harsh environment of outer space, vacuum and temperature extremes.

Advanced suits better regulate the astronaut's temperature with a Liquid Cooling and Ventilation Garment (LCVG) in contact with the astronaut's skin, from which the heat is dumped into space through an external radiator.

Another layer is composed of spandex, an elastic wearable polymer

The innermost layer is made up of a Nylon tricot material

Space-suit

Dacron—a type of polyester—is used for a pressure-restraining layer.

Smart Military Uniform

The uniform is equipped with optical fibers, which can detect an injury such as by bullet and send information to the concerned center.The signal’s magnitude would depend on the force applied on the fiber that can be considered as the severity of the injury and priority of treatment can be decided by this information.

The US military’s land warrior program is arming soldiers with the uniform containing protective gear and body armor and computer.

This would help also in reaching or locating injured soldiers in the battlefield or rescue operation.

Smart Military Uniform

The headgear shows battle plans soldier position transmitted over a wireless LAN. It also consists of a microphone.

The radio cum computer on the back or on the arms is powered by lithium battery. At chest, another strap contains Solider Control Unit for interfacing with computer.

Speedo Fabric (Shark Skin)

SPEEDO Intentional, Japan has developed mimic of sharkskin, which ensures easy swimming

The fastest aquatic creatures have one thing in common: sleek, durable skin that lets them slice through the water. Following their lead, the speedo fabric has been developed.

In addition, this fabric is knitted with 3-dimenssional V-shaped groove with 3-D knitting principal.

Speedo Fabric (Shark Skin)

The sharkskin is made from specially developed polyamide and Lycra fibre coated with Teflon to prevent water penetration

With help of this V-shaped groove, the friction between water and swimmer is negligible and drag up to zero.This increases the efficiency of the swimmer by 8-10%.

Smart Shirt

This shirt is equipped with motion sensors; it can provide feedback about the wearer’s movements or postures.

Such information is helpful in rehabilitation or sport applications, where it is important that certain movements are executed correctly.

The life shirt system is a comfortable garment that can be worn under normal uniform and it can automatically and continuously monitor over 40 physical signs such as respiratory rate, ventilation, swallow counts, arterial pulse wave, and heart rate.

Smart Shirt

For example, rehabilitation exercises need to be performed in clearly a defined motion sequence, with the correct speed and a defined amount of repetitions.

Jogging suit

The Brussels, Belgium based research lab, Star Lab has developed a suit which monitors the heart beat, and then plays certain type of music, adopting the rhythm to push the wearer faster or slower.

A mobile phone in clothing can send the data by e-mail to wearer’s club.

This suit has several layers with heat sensor and microphones embedded in cuffs and collars to measure light and sound.

Jogging suit

A microchip card inside the suit can sense when jogger is tired and suggest him to continue or rest.

From outside it measures the weather and from inside it monitors wearer’s biophysical state by analyzing this internal and external characteristics, the jogging suit can suggest the duration and intensity of exercise

In addition, if something dangerous does happen it can intimate a doctor.

Wind stopper fabric

These types of fabrics are used during trekking on mountain in windy weather.

Windproof clothing prevents convective heat transfer. Convective heat loss is a significant factor in causing discomfort.In cool or cold, windy condition windproof clothing keeps us warmer by preventing convective heat loss (the wind chill effect) and the discomfort associated with it.

Wind stopper fabric

Wind stopper products are typically coated with DWR (Durable Water Repellent), which provides them with a modest degree of water resistance.

When wearing a windproof layer, we can maintain our warmth with less insulation in windy conditions.

Sun Protective clothing

Sun protective Tshirts are the best and most reliable protection against the sun. They are recommended by both the World Health Organization and the dermatologists.It contains  no chemicals that could harm the skin nor the environment.

The protection from UV radiation that textiles provide is indicated as a UV PROTECTION FACTOR(UPF) .

Sun Protective clothing

They are slightly extensible and do not loose their shape in time. They resist sand and chlorine abrasion

Beyond the amazing UV protection (UPF50+), these t-shirts dry up really quickly and absorb sweat

AdvantagesLight weightDurableWashableIntegratable with human bodyPierce resistantWater resistant yet breathableTracking/communication systemsMonitoring systemsUsable in security authentication

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DrawbacksNeeds to be chargedBulkyExpensiveYet to be commercially recognized

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ConclusionTextiles represent an attractive class of substrates for realizing wearable bio-sensors. Smart textiles describe the convergence of electronics ,nanotechnology, information technology into fabrics which are able to sense, compute, communicate and actuate. As many different electronic systems can be connected to any clothing, a wearable system becomes more versatile, and the user can change its look depending on environmental changes and individual preference.

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