Smart textiles are generally used as energy saving fabric in tent roofs, as threads with piezo energy properties to generate very small amounts of energy or as heat conducting fibres in heated coatings for wind turbine rotor blades. Today the so-called intelligent or smart textiles have gone beyond their original purpose as an envelope and are increasingly incorporating additional energy and heat functions so as to improve the sustainability of the products used.
For a number of years the prediction has been for a big growth potential. Now with the increasing importance of energy-related issues, intelligent textiles are breaking away from being niche based and becoming part of our everyday world.
For some time organic photovoltaics have been regarded as an interesting potential, yet the products supplied hitherto were not sufficiently durable and not very efficient. All this is now about to change following new and recent developments. Pigments in textile structures in particular convert light into electrical energy and offer numerous advantages compared to rigid solar cells. They are flexible, breathable and easy to fabricate. The modular systems can be used for autonomous energy supply in textile micro-systems, for example. They are a suitable alternative where rigid solar modules and films cannot be used.
The TEXSOLAR project at the Textile Research Institute Thuringia-Vogtland (TITV) in Greiz has been successful in converting energy directly on modified textiles for the very first time. If this can be done under production conditions, it will be possible to manufacture cost-effective textile sensors that operate autonomously and have long-term durability in addition to highly flexible, electronic components for use in medicine and technology.
The textile pigment-based solar cells are suitable for microsystems with small solar surfaces to supply energy to interactive textile components with an power consumption of up to 100 µW. “Textiles that autonomously convert solar energy into electrical power will make life easier for future generations in many fields,” said Dr. Andreas Neudeck, acting departmental head of research and development at TITV Greiz.
In the years to come we will see therefore the emergence of energy autonomous products that are able to harvest energy from sources in the world around us. In the textile field, in addition to these pigment-based and thin film solar cells, materials with piezo-electric properties are especially suitable for energy harvesting, that is to say the generation of very small amounts of energy. These materials are able to convert deformations into electrical voltage.
At the Fraunhofer Institute for integrated switches (IIS) electrical switches are currently being developed for use with piezo-electric fibres as part of the European PIEZOTEX research project. With their value for intelligent textiles researchers promise numerous potential uses. The development of a PVDF thread should make it possible, for example, to integrate electrical components in textiles that are able to generate their own energy supply through movement, e.g., during sport.
“We are also thinking of textiles that facilitate particular movements or work processes or of concepts that enable autonomous operation through the supply of piezo-electric energy,” explains Dr. Peter Spies, Head of the Energy Harvesting Group at Fraunhofer IIS.
The application of a CNT-based heated coating (CarboeTherm) by FutureCarbon GmbH from Bayreuth shows that textile material innovations can be used in the context of energy generation to produce energy without unessential outage times. The company develops functional coating systems through integration of carbon nanofibres CNT and with the aim of improving the properties of a material.
Carbon nanotubes are a shining example of the new carbon materials. They are a particularly durable configuration of a hexagonal honeycomb structure along a tube, extremely strong with outstanding electrical and thermal conductivity. As additives in polymers they are able therefore to conduct heat and to transform a surface coating into a surface heater.
As a result, when applied to rotor blades of wind turbines, carbon nanotubes can be used in winter for de-icing and to reduce unessential outage times. With their hazard-free low voltage CNT-heated coatings can also be used in the form of surface heaters for motor vehicles, in the underfloor heating systems of motor homes or wet spaces as well as to heat hoses in medical technology.
“By selecting the appropriate bonding agent it is possible to determine the maximum operating temperature of the Carbo-e-Therm system and in this way to tailor the perfect solution to the customer’s particular application,” emphasises Dr. Walter Schütz, Managing Director of FutureCarbon GmbH.
As the industry’s leading global trade fair, Techtextil 2013 (June 11-13) will bring together all product groups and application areas for technical textiles at one central venue. It is where industry, research, developers and trade can find the whole gamut of issues relating to technical textiles and nonwovens in all its disciplines on a globally unique platform for innovation. It takes place every other year. This year there is a special focus on the potential uses of intelligent textiles in the context of energy products.
Texprocess, a leading international trade fair for processing textile and flexible materials, will be held concurrently with Techtextil from June 10 to 13. At Texprocess, manufacturers from all over the world present their high-tech solutions for the apparel industry and textile processing. The spectrum of products and services on show ranges from design, pattern development and cutting, via sewing and joining, to embroidery, textile dressing, finishing and logistics.
The première of Texprocess in 2011 attracted 326 exhibitors and 17,000 trade visitors, 6,500 of whom were from Techtextil.