Today intelligent clothing and accessories can be more or less bought “ready to wear”. Examples include bags with integrated solar cells that charge laptop batteries and skiing gloves that also function as telephones. What is technology capable of today?
Linz: The two products you mention belong to a group that I call transitional products because they deploy conventional technologies. They involve sewing the electronic modules into bags, inserting them into the lining or simply sticking them on. The modules are conventionally connected via cables – although these can be hidden. This is completely adequate for many applications, and also most cost-effective.
In future, however, we will see further applications that require a higher level of integration. These are products where it is important to retain the textile character, for example pleating or washability with the electronics. We are currently developing technologies to connect miniaturized electronic modules with conductive fabrics. This enables for example sensors to be integrated into clothing or different modules to be connected via electrically conductive textiles.
Is this just a bit of technical fun and games or do people actually like to wear this type of garment?
Linz: The two aren’t mutually exclusive. The two products you mention can certainly be located in the lifestyle segment where design is the top priority. However, they also slot well into the category of work clothing. For instance, a telephone glove could considerably assist the work of technicians in northerly regions.
Where are the greatest challenges currently in the development of intelligent textiles?
Linz: I see two major challenges. First we have not yet been able to develop simple product ideas that can be implemented using conventional technology and are successful in the market. Second there are lots of ideas for very complex products. For example, sensor clothing that monitors vital body functions in at-risk patients and notifies the doctor in the event of an emergency. These applications require new knowledge in many different disciplines, such as medicine, telecommunications, or connection and sensor technology.
Further, such products give rise to ethical, social and legal questions that still need to be answered. By way of example, an ECG and a record of the acceleration data can be used to derive information on how often someone does sport, how long they spend lying around on the couch and how often they have sex. This is of course very personal information. Who should be allowed to read and analyze this data? Who would patients trust with this information? Should it be analyzed mechanically? And who bears the responsibility if the machine analysis is wrong?
In the scope of the EU ConText project you are developing a vest that, among other things, can measure muscle tension and consequently can reduce back problems. How exactly does that work?
Linz: Whether the vest will ever relieve back problems is still completely unknown. For one of the project partners – the University of Leuven in Belgium – we are developing a tool that enables research into the interaction between physical and psychological stress. This tool is a vest that creates an electromyogram without direct skin contact, that is, it measures the electrical muscle activity with capacitive electrodes integrated into the textile. The key concepts here are “contact-free” and “textile integration”. This solution enables examinations without adhesive electrodes or many cables. Such invasive technology would influence the test subject and falsify the results.
What are the technological challenges here?
Linz: The vest is a very complex application, meaning that we have had to develop innovative technologies in a number of fields with our partners. Philips, for example, developed algorithms that make capacitive measurements more robust. The TU Berlin and the Fraunhofer IZM in Berlin developed methods to combine electronics with different conductive structures and to encapsulate these so that the jacket can be washed, for example.
The TITV Greiz textile research institute manufactured capacitive electrodes from multi-layer fabrics with conductive threads. The Dutch organization for applied scientific research produced a sensor by printing conductive structures onto textiles.
What further areas of application do you see for your technologies?
Linz: If all we were interested in was producing a tool to research stress, we wouldn’t have gone to so much effort. The new technologies can therefore also be used in other applications. For example, the Finnish partner Clothing Plus is developing a gaming application based on the ConText results.
We at Fraunhofer IZM are currently extending the connection and encapsulation technology for an industrial client in the entertainment sector. The capacitive measurement as improved by Philips can also be used in non-textile applications such as chairs. In addition to electromyography, it can also measure many other bio-electrical signals such as the pulse rate.
The ConText project will run until the middle of the year. When will the technology be market-ready?
Linz: I anticipate that you will find some ConText developments in products within five years. There are already some concrete plans in place that I am not at liberty to discuss.
What other sectors benefit from the new technologies?
Linz: As I see it “true” textile integration continues to benefit applications where there is a problem that can be better solved with a textile surface rather than a single component such as a cell phone. This includes for example measurement of bio-electrical signals at different points on the body. Displays are a further possibility. Large screens are best suited as displays. However, they need to be easily stowable for mobile applications. Textile displays will solve this dilemma.