Electroactive fabrics for interactive clothing
Imagine if your clothes could send you a feeling. This is the potential for haptic clothing, a type of smart textile able to stimulate touch. This kind of technology could make virtual reality seem even more real, along with a whole host of other applications: from enhancing athletic training, to aiding navigation for the visually impaired, even to anti-vibrating suits for those with Parkinson’s disease. “I personally want a jacket where I can send a hug to someone,” says Angelika Mader, associate professor in the Human Media Interaction group at the University of Twente and WEAFING project coordinator. “This is an example of social touch with well-being as a goal and domain,” she explains. In the EU-funded WEAFING project, Mader and her colleagues developed new yarns that can contract when current is applied to them, bringing haptic clothing one step closer to reality.
Electroactive fabrics for interactive clothing
The new ‘electroactive’ yarns can be used to make textiles by weaving or knitting. “These are both very old techniques for textile production, but throughout history yarns did not do anything, they were simply passive,” adds Mader. “Textile constructions where the yarn is active are a completely new challenge.” The design of the yarns means that only very low currents, from 1–1.5 V, need to be applied to stimulate contraction and sensation in the wearer of the textiles. “There is other technology that requires high voltage which we prefer not to have in wearables,” notes Mader.
Yarn development and bio-friendly gels
During the project, the team worked on the technology itself and the fabrics. Before the project, the team already had a yarn that could contract in an ionic (charged) solution. The team created gels that can be added as a coating to the yarns and that can provide the ions, so that the actuators – components that contract when they are switched on – are not working only in a solution, but in air as well. The researchers created several gels, the final one of which is bio-friendly and can also be used in textile machines to coat yarns. This is key if the yarn will be produced at scale.
Understanding haptic perception
The project also explored haptic perception in wearers. “No research was done before on how much pressure we need to feel a touch, and how much to experience it as comfortable,” remarks Mader. “With user tests, we determined detection thresholds for pressure on the arm, and found out that not the force alone is relevant, but also the size of the area of touch,” she adds, explaining that this is part of a field known as psychophysics. “This knowledge is relevant when eventually designing garments.” In the end, the team created a demonstrator: a Social Touch Sleeve where touch can be sent to another person, for example during a video call. The team will now develop the technology further. The textile developed so far generates force, but there is a need to create more of it for some users. “The newest results since WEAFING are already better than those from our demonstrator,” says Mader. “I expect that in about two years, we’ll have samples that can provide the full pressure that we need for haptics. From then on it is product development.”
Keywords
WEAFING, haptic, textiles, electroactive fabrics, interactive clothing, bio-friendly, perception, technology
