Smart Textiles and Intelligent Textiles
Smart textiles are textiles that can sense and react to environmental conditions or stimuli from mechanical, thermal, chemical, electrical, or magnetic sources. Smart textiles may combine fabrics with glass, ceramics, metal, or carbon to produce lightweight hybrids with incredible properties. Sophisticated finishes, such as silicone coatings and holographic laminates, transform color, texture, and even form.
European Union (EU) Projects in Smart Textiles and Clothing
A number of EU projects in smart textiles have been supported the last decades. Most of the supported projects are within the health monitoring area. Another type of project at EU-level develop enabling technologies for smart textiles, for example stretchable electronics, integration of electronics in textiles, technologies that are necessary for the development of smart textiles applications.
The smart textiles system consists of two types of materials, the textile and the electronics. While textile materials and structures are soft, pliable and flexible electronics are hard and brittle. Since the integration of electronics into textile structures is crucial in a smart textile system the development of new technologies that enables the convergence between textile and electronics is required. Another challenge in these projects has been to make use of the already developed sensor technologies in the field of electronics and investigate of these sensors could be applied and integrated in textile structures.
Sensor Materials And Structures
The basis of a sensor is that it transforms one type of signal into another type of signal. There are different materials and structures that have the capacity of transforming signals.
- A thermal sensor for examples, detects thermal change.
- Other examples are stimuli-responsive hydrogels that swell in response to a thermal change.
- Humidity sensors that measure absolute or relative humidity. Pressure sensors convert pressure to an electrical signal.
- Strain sensors convert strain into an electrical signal.
- Chemical sensors are a series of sensors that detect presence and concentration of chemicals.
- Biosensor is a sensing device that contains biological elements which is the primary sensing element. This element responds with a property change to an input analyte, for example the sensing of blood glucose levels.
Actuator Materials And Structures
- Actuators respond to a signal and cause things to change colour, release substances, change shape and others. Chromic materials, which are widely used in smart textile applications, as colour change material, change their optical properties due to stimuli like temperature, light, chemical, mechanical stress etc.
- Stimuli-responsive hydrogel is a three-dimensional polymer network that responds to stimuli such as pH, electric filed or temperature changes. The response is swelling and they are also able to release chemicals when required [Lam Po Tang, Stylos].
- Shape memory materials transform energy, mostly thermal, into motion and are able to revert from one shape to a previously held shape. There are two types of shape-memory materials, Shape Memory Alloys, SMA, based on metal, and Shape Memory Polymers, SMP.
- Electroluminescence materials are light-emitting materials where the source of excitation is an applied voltage. Light-emitting diodes convert electrical potential to light and are often used as actuators in smart textile applications.
- Besides sensors and actuators there is a group of materials that conducts electricity, these are the conductors.
- They are usually not categorised as sensors or actuators but, due to their conductive properties, they are useful in smart applications.
- As pathways to transferring data information but they are also important components in the creation of sensors and actuators.
- Metals, like silver and copper are the most conductive materials. Carbon has a good conductivity and is used both in its own pure form but also blended in other material to enhance their conductivity for example silicone.
- Conductive polymers are organic materials that are able to transport electricity. There are difficulties to be faced both in the processing of these materials as well as a non-sufficient conductivity for most applications, however in the creation of sensor conductive polymers could be used since these applications are not always dependant on high conductivity
- In terms of intelligence, the smart system will require a central processing unit that will carry out data to the different sensors and decide action on the basis of the results.
- The processing unit consists of hardware and software where the software causes unique dynamic behaviour in real time.
- The traditional package of computing material is a computer that allows data processing as well as communication.
- The processing unit is a complex structure of electronic circuitry that executes stored program instructions.
- Included in this structure are; integrated circuits, secondary storages, power supply and communications technologies.
- Most integrated circuits are made of silicon because of the semiconductor properties of this substance. Another type of circuit suitable for wearable application is organic electronics.
- These materials are flexible, lightweight, strong and have a low production cost, however the electronic properties of the conducting polymers do not match those of silicon.
The most common power sources are AA batteries or lithium batteries. Other forms of power supply such as flexible thin batteries have been considered and investigated.
Health monitoring for medical assistance
Health monitoring is a general concerns for patient requiring continuous medical assistance and treatment. In order to increase mobility for such patients a huge effort has been pursued for the development of wearable systems for the monitoring of physiological parameters such as respiration, cardiac activity or temperature of the body. Smart textiles play a growing role in these developments since they are well suited for wearability and washability that ensures the comfort for the user.
- The Wealthy project was one of the first EU-projects aiming to set up comfortable health monitoring system based on textile sensors, advanced signal processing techniques and modern telecommunication systems.
- The focus areas were cardiac patients during rehabilitation but also to assist professional workers to consider physical and physiological stress and environmental and professional health risks.
- In this project two types of sensors were developed for the integration in garments. The first sensor was a lycra based fabric coated with carbon black and rubber for the recording of breathing rate. The other sensor was made of metal-based yarns for the monitoring of heart rate.
- All sensors were integrated in a fully garment knitting process. Together with the textile development a miniaturized short-range wireless system was developed in order to transfer biophysiological signals from the garment to a computer or a mobile phone.
- The Proetex project aims to rescue firefighters and civil protection workers using the wireless monitoring of heart rate and temperature measurement.
- In this project, the heart rate was measured using integrated textile sensors while temperature was measures via integrated conventional temperature sensors.
- The concept consists of a belt and a tight-fitting t-shirt and a wearable interface for monitoring the operator’s health status and potential risk in the environment.
- The objective of the Stella project is the development of stretchable electronics for large area application for use in health care, wellness and functional clothes and for integrated electronics in stretchable parts and products.
- Stretchable electronics includes the integration of electronic components, energy supply, sensors and actuators or display and switches on a stretchable substrate with stretchable conductors.
- The main technologies that were developed in the project as new stretchable substrate with stretchable conductors, assembly technologies in stretchable substrates and finally integration methods for electronics products.
- The goal of Dephotex project was to explore and develop photovoltaic cells in order to get flexible photovoltaic textiles based on novel fibers allowing to take benefit from the solar radiation so as to turn it into energy.
- Since the development of first photovoltaic cells, solar energy is being an object of continuous research focused on improving the energy efficiency as well as the structure of photovoltaic cells.
- The research is based on novel fibers with conductive properties as substrate of the structure of flexible photovoltaic cells and materials and techniques in order to get flexible photovoltaic textiles.
Commercial activities in smart textile and clothing
- Despite an extensive research effort in several projects for over 10 years there are only few smart textile clothing products on the market and the volume of business, if declared, seems to be modest in the context of fashion and clothing.
- However, there are some new established companies focused in the development and commercialization of smart textile clothing. An interesting aspect in these efforts to commercialize smart textiles is the interdisciplinary collaboration between companies in fashion and electronics respectively.
- Besides pure fashion companies there are some companies established that sells know how to integrate electronics into textiles and clothing.
Fashion and clothing companies
- Clothing + [Clothingplus] is a developer and producer of textile integrated sensors for several brands in the sports and medical area.
- The company does not develop the whole system, they develop and produce tailor-made textile structures and products that can measure anything on the human body to customer who develop required hardware and software in order to construct the final measurement system.
- The company created the first heart rate sensing shirt already in 1998 and in 2002 Clothing plus started mass-producing their heart rate sensor strap in their factory in china.
- Today clothing plus produces millions of sensor products every year to brands like Suunto, Adidas, Garmin, Philips and Timex. Clothing plus is focused on both sports and health care.
- Cute Circuit [CuteCircuit] is a fashion company based in London specializing in design of interactive fashion.
- The CuteCircuit product line includes Prét-à-Porter Collection, Haut Couture Collection and Special projects for unique performances.
- Most of the garment design focus on the clothing using LED Technology and reflective materials, for example the Twinkle Dress Line. But there are also other approaches for example the Hug Shirt that enables people to send hugs over distance.
- The shirt is embedded with sensors that that feel the touch, the skin warmth and the heartbeat rate of the sender and actuators the sensation of touch, warmth and emotions of the hug to a shirt of another shirt.
- Hövding is a Swedish company selling their patented product Hövding, a bike helmet integrated in a collar.
- Hövding is a collar worn around the neck and the collar contains an airbag that the user will only see when there is an accident. The airbag is shaped like a hood, surrounding and protecting the bicyclist’s head.
- The trigger mechanism is controlled by sensors, accelerometers and gyros that pick up and reacts on abnormal movements.
- When an accident occurs and the airbag inflates and surrounds the head tanks to an integrated gas inflator using helium, the inflator is similar to those used in motorcycle helmets with an airbag system.
Moon Berlin is a German fashion company based in Berlin with the main idea to combine light technique with high fashion to create dynamic light and shadow effects.
The collection is made in cooperation with Frunhofer IZM, Stretchable Cricuit and a DAAN design studios.
- Myontec [Myontec] is a company producing system for the monitoring of the performance and capacity of the muscles.
- The company portfolio consists of a system based in trousers and shirts integrated with sensors and different modules for the measurement and handling of measured data.The trousers are recording different muscles such as quadriceps,hamstrings, gastrocnemius and gluteus.
- Textronics [Textronics] is specialized in wearable electronics and textile sensors with a certain focus on sports performance.
- The company is incorporated in the Adidas group as Adidas Wearable sports. Their main product is the nuMetrex, a sportsbra with integrated textile sensor for the recording of heart rate.
- The core technologies are fibres, films and coatings that react to electrical, optical or magnetic signals embedded in knitting, woven or non-woven textile structures.
- The sensor portfolio consists of four groups of components. The first is the textile sensors used to monitor heart or breathing rate. The second is a family of conductive elastic yarns, which are building blocks in for example sensors and interconnects. These sensors consist of conductive nano-composite elastomeric polymers that exhibit changes in electrical conductivity as the material is stretched. The last group of components is conductive ribbon that attach to standard electronic connectors.
- They have also started 3d draping and virtual dressing room.
- Utope is a Austrian company creating smart clothing products by integrating wearable electronic systems into urban wear.
- Their only launched product so far is The Keep Safe Backpack including an alarm system based on stretchable electronic system developed by Fraunhofer IZM and a lightning jacket.
- The alarm system monitors all pockets and if they are opened unwanted there an alarm tone and a visual signal of red light will warn the user.
WarmX [WarmX] is a manufacturer and distributor of heated knitted underwear system. The company has an own worldwide-patented technology for heating textiles called warmX-technology and “ know how” and partners in both textiles and electronics. The underwear is knitted with silver coated fibres in the trunk and neck areas and a battery mounted on the waist supplies the power.
- Moritz Waldemeyer [Waldemeyer] is a British/German designer and engineer whose work is fusing technology, art, fashion and design. Waldemeyer collaborates with many of the top architects, artists and fashion and designer such as Ron Arad, Rihanna Hussein Chalayan.
- As a part of the Olympic closing ceremony Waldemeyer conceived a collection of LED embedded carnival costumes. The LED formed lights moving simultaneously with the music.
- The collaboration with the internationally regarded fashion designer Hussein Chalayan has resulted in a set of clothing combining fashion and technology.
- The laser dresses embellish Swarowsky Crystals that are deflected by laser beams. The video dresses are embedded with 15000 LEDs and the dress displays different silhouettes of sharks in the sea or a rose blooming and retracting.