Smart Textiles: Past, Present, and Future

Lieva Van Langenhove*Department of Textiles, Ghent University, Ghent, Belgium

Abstract

Smart textiles have been around for 15 years now. After the hype, reality has come. In spite of hugeinvestments in research and obvious potential of applications, only few products have made it to themarket. This presentation will describe the evolution so far and further perspectives as well asactions needed to proceed. Challenges and opportunities will be highlighted using specific cases.

Keywords

Smart textiles; Markets; Challenges; Technologies

Introduction

The concept “smart material”was for the first time defined in Japan in 1989. The first textile materialthat, in retroaction, was labeled as a “smart textile” was silk thread having a shape memory. Thediscovery of shape-memory materials in the 1960s and intelligent polymeric gels in the 1970s werehowever generally accepted as the birth of real smart materials. It was not before the late 1990s thatintelligent materials were introduced in textiles. It is a new type of products that offers the samepotential and interest as technical textiles.

The definition of smart textiles is not an obvious topic. One can distinguish between functionaland smart materials, smart materials and smart textiles, and smart textile systems and electronictextiles. Typical functions of smart textiles are at least sensing and reacting, possibly also dataprocessing, communication, and energy supply. This makes the textile passive, active, or very smart.A working group within the CEN committee on textiles (TC248 WG31) has published a technicalpaper with the terms and definitions of smart textiles.

Regardless of the definition, smart textiles have become a multidisciplinary and promisingresearch subject for many research groups all over the world.

The Past

The first generation of intelligent clothing uses conventional materials and components and tries toadapt the textile design in order to fit in the external elements. They can be considered as e-apparel,where electronics are added to the textile. A first successful step toward wearability was the ICD+line at the end of the 1990s, which was the result of the cooperation between Levi’s and Philips. This

*Email: Lieva.vanlangenhove@ugent.be

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line’s coat architecture was adapted in such a way that existing apparatuses could be put away in thecoat: a microphone, an earphone, a remote control, a mobile phone, and an MP3 player. The coatconstruction at that time did require that all these components, including the wiring, were carefullyremoved from the coat before it went into the washing machine. The limitation as to maintenancecaused a strong need for further integration.

Further evolution has included three trends:

• Search for new concepts and technologies for a wide range of applications• Making electronic components compatible with the textile substrate• Transforming electronic components into true textile structures

At the beginning of the new millennium, three research labs were pioneering in the field ofdeveloping real smart textile products: Georgia Tech (wearable motherboard), University of Pisa(Wealthy (IST-2001-37778)), and Ghent University (Intellitex baby suit [1]). The three of them weretargeting textile electrodes for monitoring heart and respiration rate, for different applications:military, sports and health, and babies, respectively. Optical and electrical carriers were used.

At UGent, for instance, this resulted into a stand-alone baby suit for monitoring sudden infantdeath syndrome, as illustrated in Fig. 1.

The Intellitex Textrodes consist of stainless steel fabrics; respiration is measured viapiezoresistive stainless steel staple fiber yarns. A coil of stainless steel yarn is embroidered on thebaby suit. It creates an inductive link with a second coil, which is embedded in the mattress. Thelatter can be connected to external power supply, data processing units, further communicationdevices, and response devices such as an alarm. The conductive link thus provides the baby suit withenergy while at the same time transferring the data. The baby pajama only contains a small processorand no battery. This approach overcomes some major challenges in terms of washability of thetextile product.

The first generation of projects demonstrated the potential and the strengths of smart textileproducts. Many other universities and research centers initiated projects on a wide variety of smart

Fig. 1 Intellitex baby suit

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textile topics. Materials were based mainly on stainless steel fibers and optical fibers. As such fibersare not very compatible with regular textile fibers from the point of view of processing (abrasion),product properties (hardness, stiffness), and behavior during normal use (separation of materials);soon it became clear that new conductive materials and structures had to be developed. In responsenew types of conductive materials were achieved by adding nanoparticles into the polymer, bycombining elastic filaments with nonelastic conductive fibers [2], and by coating fibers with metalliclayers [3].

Some of the new materials even turned out to have sensor properties [4].So overall, these projects have led to developing improved materials, sensors, and actuators.Unfortunately some problems showed to be more difficult to solve than foreseen: integration,

interconnections, and washability. The wearable motherboard already used the textile product initself as platform for interconnecting the active components. Further progress was achieved by ETHZurich [5]. Other suggested solutions for integration and washability include packaging andstretchable electronics [6]. In addition full textile-compatible conductive materials are lacking.

Most of the projects target applications in the area of health care or protection. In such domains theadded value of smart textiles is obvious: it can detect threatening conditions in an early stage andthus send out a warning to seek for help or protection.

From the beginning Europe has started investing money in research on smart textiles. Severalnetworks have been set up for coordinating the efforts and for identifying needs and opportunities.As a result Europe is currently in the lead.

Present

The Technology PerspectiveAn OverviewAs stated before, smart textiles have basically five functions that have to be integrated andinterconnected in a cost-effective way.

In each of these areas, R&D has been carried out and results are available to a certain extent.Some of the examples given hereafter illustrate the impressive achievements today. A detailed

overview is given in 7.

Sensors A lot of work has been done on sensors. Awide range of sensors is already available, withvariable levels of textile transformation and at least at the prototype stage.

The first sensors were based on electromagnetic measurements. Conductive textiles were and stillare used for monitoring heart rate. This was a major aspect of the EU project MyHeart (www.hitech-projects.com/euprojects/myheart). Within the European project ConText (www.hitech-projects.com/euprojects/context), a contactless sensor has been developed. The consortium uses embroideryand lamination technology to produce EMG sensors for monitoring stress in professional situations.Piezoresistive strain sensors indicate respiration rate [8] or motion [9]. Optical systems are used aswell. They use direct methods through optical fibers with Bragg grating (www.ofseth.org).

Pressure can be measured using contact, piezoresistivity, or capacitors. Contact-based pressuresensors include a variety of mechanisms. Conductivity of textile structures is determined by a rangeof mechanisms such as:

• Conductivity of the material itself• Its sensitivity to deformation

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• Contact resistance• Number of contacts between fibers and yarns

Material properties and structure of yarns and fabrics determine these effects. Pressure willobviously affect contact resistance leading to qualitative and quantitative effects. Intrinsicpiezoresistive materials can be based on the quantum tunneling effect, such as QTC materialsfrom Eleksen [10].

Detection of chemicals has been studied in the European project Inteltex, using change inconductivity by swelling of CNT charged fibers as a basic mechanism (www.inteltex.eu).

Color-changing dyes indicate pH, which is a useful tool for monitoring proper healing of burningwounds [11]. Many other color-changing dyes have been reported.

Detection and analysis of sweat has been the topic of the EU project BioTex [NMP-2004-IST-NMP-2, 16789].

Actuators Actuators can be considered as reverse sensors: sensors are expected to transform animpulse into a readable signal (mostly electrical), whereas actuators should respond upon a signalthat will be mostly electrical. Actuators should respond as expected, consistently, fast, and energyefficient. Today this is still an important challenge.

Optical actuators emit light.Initial developments have focused on the integration of optical fibers [12]. LEDs light optical

fibers. The light is released in areas where the cladding layer has been damaged. By integrating suchfibers in a woven or knitted structure, lighting areas can be achieved. The color of the LEDdetermines the color of the emitted light, so this can be altered. The location is fixed by the locationof the optical fibers as well as the damaged areas. In addition the system is rather complex, as manyparameters have to be right: LED, power supply, interconnections, optical fibers, and lighting areas.Therefore, direct emission of light seems more appealing.

The Philips program Lumalive has intended the integration of LEDs in combination with textiles,such as clothes and furniture [13]. Further work has targeted miniaturization and textile integration(www.stella-project.de). One step further is making the textile itself light emitting [14]. Challengesat this moment are that organic active layers are not very efficient yet, so the yield is still low, and thatthe material is very sensitive to oxidation.

Nowadays, ribbons containing LEDs are available on the market [15]. They can be integratedeasily in a textile product.

Another approach is using electrochromic dyes [16]Electrical actuators use textile electrodes for electrostimulation. Stimulation can range from

tactile impulses over electrochemical reactions up to active contraction of muscles.They consist of two electrodes between which an electrical field is applied. The conditions of

current depend on the targeted effect.Some reported applications are:

• Fitness, wellness, and pain relief: standard devices for home use are available on the market.• For training purposes and physiotherapy.

• For treating pain and/or swelling, this treatment is sometimes referred to as TENS or transcu-taneous electrical neuromuscular stimulation.

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• It stimulates weaker muscles to contract during exercise to improve strength more quickly.Consequently neuromuscular electrical stimulation (NMES) can significantly improve recov-ery times.

• For the treatment of specific neurological problems such as anxiety, depression, andinsomnia [17].

• For enhancing wound healing [18].

Two major challenges arise:

• There is not always much clinical proof of the positive effects of electrostimulation and theprecise conditions at which these effects can be achieved.

• At higher levels of stimulation, current concentration at the edges may occur, leading to hot spots.Appropriate design can overcome this problem [19]. In addition user appreciation for the sametype of electrodes and conditions of stimulation may range from “pleasant” to “painful” [20]. Thetextile must be properly designed for ensuring proper placement and tight contact with the body.

In few applications today textile electrodes are being used. Nevertheless textile products offer theadvantages of being recyclable and easy to use and ensuring proper positioning of the electrodes.

Thermal actuators can provide heating or cooling.Heating is fairly simple in principle: it only takes a conductive material and a DC current.One of the first examples of heating textiles is the E-CT fabric from Gorix [www.gorix.

com]. Other commercially available active heating garments are Polartec® Heat® panels by MaldenMills [www.polartec.com], the Bekinox® heating elements by Bekaert, and the Novonic HeatSystem by Zimmerman.

Although basically very simple, the main issue of heating through conductive textile materials iscurrent distribution leading to local overheating, as has already been mentioned in the previousparagraph. In heating applications, the current will concentrate in order to minimize resistance. Itwill follow the shortest path and pass by areas with lower resistance, thereby avoiding highresistances such as transfer between yarns. Considering the inhomogeneity of textile materials andthe complexity of their structure, current distribution is pretty unpredictable.

Figure 2 illustrates how such effects determine the path of current and thus heating. Temperatureis recorded by an IR camera [19].

As a result conductive yarns are integrated in a very simple pattern, being either a parrallel set ofyarns of equal length or one yarn that reciprocates over the heating area. So there is currently no easyand flexible manufacturing process for heating elements.

Cooling is a very challenging issue. Passive cooling systems use endothermic processes such asevaporation of water, recrystallization, melting, etc. (www.prospie.com). They work well, but theircapacity is limited.

The Italian company Grado Zero has embedded ultrathin tubes in textile structures through whicha cooling liquid can be circulated. An F1 pilot racer suit has been manufactured [21]. The liquid iscooled by a small Peltier element that is fixed at the backside of the suit.

Chemical actuators release chemicals in a controlled way. Several concepts are available such asmicrocapsules [22], cyclodextrins [23], hydrogels [24], and nanofiber structures [25],

Mechanical actuators do exist, but all of them have major drawbacks. They are either slow,require high voltage, cannot exhibit high forces, or are not reversible. They include shape-memorymaterials [26], multilayer structures [27], electrostrictive materials [28], or diffusion-basedelectroactive polymers. Proper design enables a variety of movements.

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Communication BAN (body area network) communication is fairly easy and electroconductive,and optical fibers and yarns can be used to this end. Wireless communication is the main challenge.Two approaches have been studied, for medium and short distances, as illustrated in Fig. 3. Themicrostrip patch antenna (left picture) is active in the SIM band, which also includes Bluetooth[29]. This allows communication with, for instance, a smart phone or laptop. Further data processingand wide area communication do not need to be handled by the textile in this way. The antenna isscreen-printed. The picture on the right illustrates an inductive link [1, 30]. It is embroidered on the

Fig. 3 Wireless textile link (a) Antenna operating in the ISM band (b). Inductive link

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Fig. 2 Inhomogeneous heating effect in a polypyrrole-coated fabric due to current distribution; left: temperaturerecorded with IR camera, right: simulated profile

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textile substrate. Such a connection only works well when the second antenna is nearby and parallel.The electrical field decreases exponentially with distance and should not exceed a few millimeters.This is an appropriate solution, for instance, for monitoring a person during sleep, where the secondantenna can be integrated in the mattress.

In the ProeTEX project, a GPS system embedded in a rescue suit allows to determine the locationof a person.

Energy Supply Energy supply can be achieved through two approaches: energy storage and energyscavenging.

Energy storage can be achieved through batteries. Capacitive or electrochemical batteries arecurrently in use. The disadvantage of capacitors is that the voltage supplied is not constant. For both,density of storage is limited, so capacity requires volume. For flat batteries, volume means surface.

Flexible batteries are commercially available. Although they are flexible, they are not breathable,so comfort is limited. Research is going on concerning textile-based batteries, but they are far frombeing commercial [31]. An example of such a battery is illustrated in Fig. 4

Energy is available in the environment under the form of heat, light, and motion. Severalmechanisms are known to harvest them.

Infineon has developed a device that harvests electricity from body heat. It was one of the firstwashable smart textile components. The demonstrator developed by Infineon has the dimensions ofa euro coin and produces enough energy for a small sensor. This means that a stand-alone sensor canbe achieved by integrating a local thermogenerator together with the sensor.

Scavenging nergy from light is a technology that is commonly used in photovoltaics (PV). Todayflexible PV foils become commercially available. It is one of the highlights of the European networkon organic large area electronics COLAE (www.colae.eu). The application of PV cells on textilesubstrates is the subject of the European projects DEPHOTEX (www.dephotex.com) andPowerweave (www.powerweave.eu).

Energy from motion can be captured in two ways, namely, using piezoelectric materials [32] andby EM induction [33].

Data Processing Data processing requires electronic components. Initial research targeted minia-turization and encapsulation. Later on, flexible boards have been developed. A major step forward isthe development of stretchable and washable electronics (www.stella-project.de). This has largelyincreased the textile compatibility.

Follow-up projects are further elaborating on this (e.g., FP7 projects PASTA [www.place-it-project.eu] and PLACE IT [projects.imec.be/pasta/node/1]).

Fig. 4 Textile battery based on PDOT-PSS

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The ultimate challenge is to develop fiber-based electronics. Several studies target fiber transistors[34, 35].

Interconnections The last challenge is integrating and interconnecting all active components. Allcomponents need to be integrated seamlessly in the textile structure. TheWearable Motherboard thathas been discussed previously is the first development in this respect. It consists of a grid of opticalfibers embedded in a woven or knitted structure; at several connectors, active components such assensors can be attached.

Based on the work of ETH Zurich [5], the Swiss company SEFAR has designed a woven textilestructure with a grid of electroconductive yarns onto which electronic components can be attachedso that the appropriate connections are achieved with a good level of durability.

Embroidery is considered as a textile technology suitable for interconnecting electronics totextiles. T. Linz [36] explored the potential and limitations in his PhD study “Analysis of failuremechanisms of machine embroidered electrical contacts and solutions for improved reliability.”

Failure happens due to breakage at the transition zone from soft to hard materials and due torelaxation of the materials causing the contact to become loose.

The first problem will become less important as active elements are being transformed into truetextile structures, such as with smart fibers (transistor fibers) or smart yarns [37]. However, electricalcontacts remain a major challenge, particularly in view of rearrangement of fibers causing thestructure to relax.

A Practical Case: The Smart Firefighter SuitThe firefighter suit is an excellent case for illustrating the status of smart textile products. It is a pieceof high-tech textiles with many active components, offering a good platform for further exploitationin other applications.

Today’s firefighter suit offers an extreme level of thermal protection. This level of protection is sohigh that the firefighter loses perception of the real danger in and around the fire. By the time he(or she) feels the heat or excessive body stress, it may be too late to get out and take off the equipmentand clothes. So monitoring of vital signs and effective intervention are needed.

In addition heat and water cannot get into the suit, but they cannot get out either. This leads todangerous conditions such as overheating by own body heat and sweat being converted into steam.

The European Commission has funded a number of research projects on smart thermal protectionfor professional use. Most of them target monitoring of vital signs and endangering ambientconditions, as well as communication tools. In addition each project approaches specific challengesin their own way:

• I-Protect (www.ciop.pl/21160.html) targets protection of firefighters and chemical and minerescue workers. The selected solution will be based on fiber-optic sensors integrated inunderwear.

• ProFiTex (www.project-profitex.eu) follows a user-centered design approach. To mitigate thenotorious problem of unreliable wireless communication in building structures, ProFiTex willexplore the approach of integrating into the lifelines used by many firefighting services, aninnovative system for data transmission and tactical navigation.

• The PROSPIE project (www.prospie.eu) targets active cooling technologies, using phase changematerials, cooling salts, and adequate design.

• SAFEPROTEX (www.safeprotex.org) addresses specific risky operations such as extremeweather conditions, wild land fires, and aid to medical staff.

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• Safe@sea (www.safeatsea-project.eu) targets advanced protective clothing for the fishing indus-try; it includes outerwear, gloves, and head protection.

The most advanced project is the ProeTEX (protective e-textiles) (www.proetex.org). ThisEuropean FP6 funded project targeted research and development on materials for smarttextiles for improved performance, on textile sensors, on communication through textiles, onthe development of prototypes including the electronic platform, and on feasibility studies offiber-based smart textiles such as piezoelectric textiles for energy scavenging and fiber transistors.Three generations of prototypes have been built (Fig. 5), consisting of an inner garment (underwear)containing sensors that have to be in direct contact or near to the body:

• Temperature of the skin• Heart and respiration rate• The composition of sweat (detection of dehydration)

The outer jacket includes (Fig. 5):

• Accelerometers that provide information on the activities and position of the wearer (standingstill, walking, running; upright or lying down)

• Thermosensors to indicate the risk of breakthrough of heat through the jacket• A GPS device to provide information on the location (in open field, for instance, when fighting

fires in the forest)• Two textile antennae that operate in the ISM band, enabling communication with a base station

within a range of 10–100 m• An electronic box for data collection and processing, a flexible battery, and a LED that turns red

when a person is in trouble• Flexible battery for power supply (Fig. 6)

Some sensors have been built upon the results of previous EU projects such as MyHeart (textilesensors for measuring heart and respiration rate) and BioTex (www.biotex-eu.com) (sensors forsweat analysis).

Gas sensors are integrated in the boots.A spin-off product is the victim patch (Fig. 7). This patch is to be put on the arm of the victims in

case of major disasters, enabling fast evaluation of urgent need for care. It uses a combination of

Fig. 5 ProeTEX underwear

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components integrated in the underwear and outer jacket: heart and respiration rate and bodytemperature.

It is compatible with the rest of the system, so data interpretation and organization of help can beorganized smoothly.

A non-technological aspect of the firefighter application is the specific situation of acquisition.Public authorities often pay acquisition, be it directly or indirectly. Procurement procedures need tobe followed. Often procurement procedures cannot cope with innovative and complex systems suchas smart firefighter suits.Within the EU project Smart@fire, novel procurement procedures are beingestablished to this end (www.smartatfire.eu).

Fig. 6 ProeTEX outer jacket

Fig. 7 ProeTEX victim patch

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The Market PerspectiveProducts on the MarketToday, a limited number of products are on the market. Their complexity varies from simple tocomplex. This offers a good range of cases with different specifications and requirements.

The price of the products has been studied in the SYSTEX project. The price depends on thecomplexity of the system. Simple monitoring products can be as cheap as some tens of euros. Whenadvanced and centralized data processing tools are needed, prices increase to hundreds of euros.High-end products for protection against harsh conditions may cost more than 1,000€. Someexamples are:

• Adidas-Polar smart shirt [38] for monitoring heart rate for sports applications can cost approx-imately 25€; this price includes only the shirt with electrodes, not the data processing unit; thelatter can cost from 40€ (small processor just indicating heart rate) up to 200€ (full connection tosmart phone with apps).

• Twirkle shirt is a T-shirt from the London designers CuteCircuit (www.cutecircuit.com). It blinksas a function of the wearer’s movements. The LEDs are integrated in the textile, whereas thesensors (accelerometers), electronics, and battery are embedded in a small pack that is attached tothe T-shirt. Its price starts from 150€.

• Smart carpet tiles SensFloor [39] from Future Shape follow a person’s behavior in a house. Fromthis a series of conclusions can be drawn such as whether a person has fallen, where a person is,presence of a burglar, etc. The price consists of the tiles, the central data processing unit, andcommunication devices. The tiles are the cheaper part. The data processing unit is more expen-sive, but it can serve up to 10 rooms. Prices start at 600–700€.

• Smart firefighter suits are high-end complex systems which must be totally reliable even inextreme conditions; all of its functions are demanding. Prices of around 1,500€ per suit have beenmentioned.

Prices are expected to evolve in time. They will drop as market grows. On the other hand, newtechnologies will bring additional features, causing the price to rise again.

This information and understanding allow companies to adequately estimate expected prices forproducts and applications.

The Hype of Smart TextilesSmart textiles are a typical example of what one could call hype. After the first projects had presentedtheir prototypes, smart textiles attracted a lot of attention from research and industry. The potentialbeing quite obvious, it immediately creates a lot of interest from all stakeholders. It does not need alot of imagination to think of appealing applications for each individual. So it became a populartheme at conferences and workshops and a source of inspiration for many research projects. It soonbecame the hope for rescuing the textile industry that has been in decline for many years. Thistechnology-driven positive hype has created extremely high expectations.

Several initiatives were set up in Europe in which industry and academia got together for mappingthe potential of smart textiles (SYSTEX [www.systex.eu], ETP [40], Prometei [41]). In these initiatives,studies have been made on market potential, research and industry players, ongoing RTD, gaps andneeds, etc. Information was collected from research projects, literature, surveys, andworkshops. It wasconcluded that in spite of the huge market potential and significant research investments, no commer-cial breakthrough has been achieved yet. In otherwords,many applications remain very niche and havenot enabled a mainstream market yet. Major reasons mentioned for this are:

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• Complementary technologies need further development (smart materials, integration and inter-connection technologies, large-scale production, design models, data processing tools, etc.).

• Business models need to be developed which are complementary to existing products in each ofthe applications.

• Established companies need to invest into adjacent markets, which might need a change in thedominant logic within the company.

The initial positive hype was technology driven, and thousands of ideas were launched. Unfor-tunately, other aspects such as business models and market approach, as described above, have beenignored. This has led smart textiles into the next phase: after the climb, the fall.

Today smart textiles have become a community, but at the same time, prototypes have shown thereal challenges and difficulties, and this has severely damped the initial enthusiasm, particularly ofindustry. This is a negative hype, which leads to the trough of disillusionment. From now on, the fewproducts that do make it to the market will restore confidence.

This typical evolution is illustrated in Fig. 8:The message today is: the potential is clear, but challenges need to be addressed for achieving real

breakthrough.

The Future: Potential and Actions Needed

PotentialThe world annual market for smart textiles is estimated around 1,000 M$ [42].

The market for smart textiles is relatively small for now, but it is growing quickly, according toSmart and Interactive Textiles. In August 2007, a report was published by US-based research firmBCC Research. In 2007, the US market for smart textiles was worth about $79 m (€53.7 m), saysBCC, but sales of conductive fabric products are expected to more than double each year through2012, when the market is expected to reach $392 m – a compound annual growth rate of 38 %.

The smart fabrics and interactive textiles (SFIT) market is estimated to reach US$1.8 billion by2015, according to new report by the Global Industry Analysts, Inc., consulting firm publishedin 2011.

When looking at the evolution of market forecasts, one can conclude that the estimated marketpotential is growing, but market breakthrough is slower than originally expected.

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Despite slow adoption rates in several markets, the demand for SFIT technology should be drivenby emergence of advanced products and new application areas with significant potential.

Axes that drive smart textiles market toward growth are:

• Development in nanotechnology, chemistry, and biochemistry will help further the potential ofintelligent textiles.

• Defense, health care, followed by the consumer sector will emerge into important markets forintelligent textiles

• Continuedminiaturization of non-textile technologies especially from the field of information andcommunication technologies and growing commoditization of computing systems will help toenable easy integration of the same into textiles and clothing for superior functions and features;miniaturization of capacitive fabric sensors enables easy integration into substrate fabrics.

Some products will replace existing non-textile products. If the added value of the textile solutionis obvious, the product can be taken to the market fairly easy because the market is already there.This is the case for sensors for heart monitoring, for instance, for sports.

In other applications, smart textiles are adding new functions, such as for the smart firefighter suit.A third category is totally new markets. These are most promising but challenging too.

The PPE SubmarketThe European Commission has identified protective textiles as a lead market [43]. The Lead MarketInitiative (LMI) is the European policy for six important sectors that are supported by actions tolower barriers to bring new products or services onto the market. Protective textiles are one of them,next to eHealth, sustainable construction, recycling, bio-based products, and renewable energies.These markets have been chosen because they are highly innovative; provide an answer to broaderstrategic, societal, environmental, and economic challenges; and have a strong technological andindustrial base in Europe. Also they depend on the creation of favorable framework conditionsthrough public policy measures more than other markets.

Let us have another look at the market for smart firefighter suits. This market consists of twosubgroups: volunteers and professional brigades. The market as such is mature, so the only possibleexpansion for a company is increasing market share. The overall market potential for both groups isillustrated in Fig. 9. These graphs, based on the total, take into account the evolution of the numberof potential users, the fraction using the product, and the product price. The latter is estimated basedon the composition of the smart firefighter suit combined with the value of components and systemsused in smart textiles. Volunteers are likely going to use a more basic version of the suit, whereasprofessional brigades will use the advanced version.

Of course market implementation will only happen if technology is ready. Within the SYSTEXproject, the following technology forecast has been established:

• Phase 1, The Basic Smart Firefighter Jacket– EN469 compatible; measurement of temperature inside and outside, including basic warning

to the firefighter; gas detection; radio control button on jacket; one device per function(no “double” devices); one standard interface protocol

• Phase 2, Monitored Smart Firefighter Jacket– Phase 1 product extended with external monitoring

• Phase 3, Heat Stress Monitoring Firefighter Jacket– Phase 2 product including below features:

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– Detection of man down; detection of air left; simple heat stress monitoring (not personspecific); position management

• Phase 4, Smart Heat Stress Monitoring Firefighter Jacket– Phase 3 product including below features:– Self-learning on heat stress– Thermoregulation

It can be expected that phase 4 will only be reached after 5–7 years.This example should be carefully looked at. Indeed one should not wait till the ultimate product is

technically feasible. One should envisage taking basic versions within reach to the market and learnfrom customer feedback.

Health-Care MarketA smart textile system could perform a wide range of tasks. In its simplest form, it providesinformation on a person and the environment of the textile itself. Adequate analysis of such datamay allow identifying health risks in the earliest possible phase. This is particularly important forhealth care and protection, as it provides a chance of preventing incidents and accidents fromhappening. When a smart textile system detects a person is at risk, it could send out an alertpreventing injuries. After an incident did happen, it could analyze the situation and provide instantaid or call for help. Last but not least, it could support and follow up the rehabilitation process oreven take over body functions that may have failed.

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Fig. 9 Firefighter markets for volunteers (left) and professional brigades (right)

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This clearly shows the huge potential of smart textiles for health care. Many projects addressmedical markets.

The ageing population brings along an increase of age-related diseases such as neurologicaldisorders, epilepsy, Parkinson’s disease, Alzheimer’s disease, cardiovascular and cerebrovasculardiseases, obesity, diabetes, cancers, wounds, ulcers, and sores.

Generally speaking, people’s interest in health and safety is increasing continuously. Follow-up ofpregnancy is a first important market; neonates and children are important target groups in thisrespect.

One can think of many roles textile products could fulfill for patients but also for caretakers. Notonly clothes could become active but also bedding, floor and wall covering, furniture, andmany more.

Cost-effectiveness has become an important issue in health care. Smart textiles are expected tobring more benefits than costs, considering its role in prevention, remote monitoring, and support.

These are important drivers that are beneficial for smart textiles.Many studies do address the medical market. It turns out to be a very difficult market. There are

lots of regulations and extensive clinical trials that have to be met. Cost calculations have to be made.Products need to be sterile. Medical staff needs to be convinced about the added value. After manyyears of research, the smart textile community is now convinced that medical applications will not bethe first big success stories.

Consumer MarketThe consumer market is huge. As explained before, textiles can replace conventional activecomponents in an existing application. A good example of this is heating blankets. They exist formany years, but the heating elements consist of conductive wires. Such wires adversely affectcomfort and cause risk of overheating as discussed before. Conductive textile structures are aninteresting alternative.

Market potential for heating blankets (simulations resulting from market studies and discussionswith companies) is illustrated in Fig. 10:

Other markets, which have not been fully explored, are gaming, cosmetotextiles, and evenfashion.

Consumer markets are heavily underexplored. Products do not have to be high-end and gadget-like products can be sold as well. Such products are not very demanding, but are rather cheap andhave limited life cycle. New business models are typically needed for such markets.

300

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Fig. 10 Market forecasts for heating blankets in Europe and USA

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ChallengesWhy Textiles?Intelligence is currently embedded in daily objects like watches. However, textiles show severaladvantages, as clothes are unique in several aspects.

They are extremely versatile in products as well as processes. The building stones of the textilematerial are fibers or filaments. Innumerable combinations of these source materials result into awhole range of textile materials. Fibers are available in a very broad range of materials: single orcombined, natural or synthetic, strong, elastic, biocompatible, biodegradable, solid or porous, andoptical or electroconductive. After treatments allow the creation of very special properties such ashydrophilic/hydrophobic nature, antimicrobial, selective permeability, etc., textile materials are ableto combine advanced multifunctionality with traditional textile properties.

Textiles are all around: clothes, decoration, furniture, bed, and so many more.Clothes are our own personal houses. They can be customised, with a perfect fit and high level of

comfort. Clothes make contact with a considerable part of the body. They are a common material toeveryone, in nearly all activities. They look nice and attractive and their design and look are beingadapted to the actual consumer group. We all know how to use them. Maintaining textile is a dailypractice: house as well as industrial laundry is well developed.

And last but not least, textiles and clothes can be produced on fast and productive machinery atreasonable cost.

These characteristics open up a number of applications that were not possible before, especially inthe area of monitoring and treatment, such as:

• Long-term or permanent contact without skin irritation.• Home applications.• Applications for children, in a discrete and careless way.• Applications for the elderly; discretion, comfort, and aesthetics are important.

However, textile products bring along disadvantages too. Generally speaking, they perform lessthan conventional components: more noise, higher energy consumption, etc. In addition require-ments for textile compatibility are challenging: repeated stretch, compression and extension duringuse, and resistance to water and chemicals during laundry.

Any product will only become a commercial success when the textile solution has a clear addedvalue.

Technological IssuesApplications in technical textiles will be built upon all components and materials of smart textiles.For other applications, the materials and technologies needed are variable.

Conductive and lighting materials, electronics, and advanced polymers will play a major role innearly all applications.

Conductive materials are expected to be available around 2016. Electronic components andenergy harvesting materials are expected to be available a bit earlier but with bigger spread.

Advanced polymers will be available as from 2013 with a very big spread (until 2021).Health applications have a lesser need for energy generation or storage systems. For clothing, in

general, there is less interest in smart functionalities, but aspects like comfort and usability are moreimportant, so there is less interest in incompatible elements like electronics, metallic, or ceramicmaterials.

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From this in combination with market perspectives and technology needs, it can be concluded thatresearch should be intensified on conductive materials and advanced polymers, whereas develop-ments on electronic components and energy harvesting should be continued.

Technical obstacles are cost, compatibility with production equipment, and ease of use anddurability, but also integration, performance, and safety and health issues. Opposite to what isgenerally accepted, not many true textile components are available. Even sensors that are assumed tobe readily available such as ECG electrodes are not fully understood yet. In addition their robustnessis rather limited.

The system approach (needed for active smart materials) is a bigger challenge than the individualelements (passive smart materials). Integration technologies in particular have to be developedfurther. Participants expect that all factors will be challenging, but cost and health and safety areparticular concerns.

The EU is considered ahead for active and very smart but less for passive smart materials. Thismight be due to the fact that projects concentrate on the application and on the more complexsystems. There should be more research on basic materials; the research interest is there.

Production can be targeting integration of textile-compatible components such as stretchablecircuits or miniaturized sensors or the production of true textile components.

Apart from the production itself, correct positioning and interconnections are needed.All production technologies require further progress in all aspects. Knitting, embroidery, and

braiding and laminating are mostly used, being the most flexible technologies. Therefore, they areconsidered as more developed. Functional performance of printing is critical. Sewing is costly,automation has to be improved, and the research interest is weak. Nonwoven is mentioned as anunsatisfactory technology, probably because of its limited flexibility. No specific processes havebeen designed for smart textiles, and on the other side, existing processes are being modified.

Regarding feasibility, extrusion is very challenging.

The Business PerspectiveFrom the business point of view, the challenge of “smart textiles” lies in the fact that the technologyis positioned on the cross border between different industries. Although the technology is anextension of textiles, its extensions enter into different industries such as electronics, sports, medical,etc. Hence, the typical business model of a textile company cannot be copied into the new industrywithout adjustment. Indeed, taking the sports industry as an example, it is unlikely that, for instance,the application of a heart monitor in a typical T-shirt will have most benefits for a sports textilecompany like Adidas, Nike, or Brooks. Instead, electronics producers such as Garmin or Polar,which already commercialize complementary products such as smart watches, might benefit morefrom the value created. If the value then needs to be split between a textile producer and anelectronics company, the chances are high that the electronics company, which sells its watch at300–400 euro rather than the textile company selling a regular T-shirt for 20–30 euro, will capturethe value. Hence, it is necessary to go beyond the boundaries of the textile industry to achieve the fullcommercialization potential of smart textiles. The smart camp [44] and lead user method [45], forinstance, provide adequate alternatives to traditional business models.

In terms of business model, one will have to accept that the source of value creation, be it“novelty,” “efficiency,” “lock-in,” or “complementary” as in the sports example, will most probablybe different for each application.

The Wide EnvironmentA smart textile product is a stand-alone system, but at the same time, it is part of a bigger system.

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As mentioned before, a specific market may impose quite some extremely strict rules of usage.Therefore, it is also important to meet such regulations and specifications.

Proving proper functioning and reliability is the first challenge as standards are lacking or notsuited for textile materials. Standardization of smart textiles is the topic of a CEN working group[CEN TC 248 WG31].

The next challenge is the procedure of acquisition. For medical applications, doctors are often theones who prescribe a solution to a patient. The medical staff is generally reluctant to change theirprocedures.

Reimbursement by health insurance can be a decisive factor.For other markets such as firefighters, acquisition takes place at governmental level or according

to procedures prescribed by public authorities. Appropriate procedures for public procurement, forinstance, are essential in this respect. Innovative procurement is the subject of the EU projectSmart@fire (www.smartatfire.eu).

Environmental aspects should be considered as well. Pioneering work on ecodesign for smarttextiles has been done by A. Köhler [46].

Ethical aspects include accessibility to technology for everyone and privacy issues.Last but not least, user acceptance can be mentioned. For some user groups such as children and

the elderly, this can be a major factor.

Summary

There are huge potential markets for smart textiles, such as health care and PPE, but not for everyproduct. The added value of the textile solution has to be demonstrated and competitive non-smarttextile solutions need to be assessed.

High-performance products do not always result into a commercial success, because manynon-technological aspects need to be addressed as well, such as directives and standards, societaldrivers, marketing, and sales.

Many technologies are available at prototype stage. They have to be taken one step further interms of robustness and large-scale manufacturing.

New business models need to be addressed too.

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ISBN 97890-6562-335-5

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