Textination Newsline

For many years researchers from Nordic countries have worked for making textile industry more sustainable. Now there are prototypes of cotton which can clean itself and of textiles which are created of invasive lupines.  

How could future clothes and textiles become more ecofriendly, smart and sustainable? A research group from Nordic countries has tried to figure out this for many years and in October the prototypes they have made were presented in an exhibition in Turku.

A doctoral researcher Alicja Lawrynowicz from Faculty of Technology at the University of Turku has been developing two different smart textiles. In one of the projects researchers have created a cotton fabric which can clean itself without water.

This is possible because the fabric has been treated with mineral called zinc oxide.
 
The mineral forms a self-cleaning layer and stains on the fabric disappear when they are exposed to the daylight, in other words ultraviolet light. If stains disappear by themselves, it reduces the need of washing and garment burdens nature less.

Here you can see how the stains gradually disappear on the white cotton fabric that has been treated with zinc oxide.

In the other textile project, researchers have managed to develop non-toxic textile print which changes its colour when it is subjected to sunlight. Mineral hackmanite, which reacts to ultraviolet radiation, is used here. The mineral does not originate from mines but is created in a laboratory in Turku.

For first time ever, hackmanite is now used in textile prints. The mineral works as an ultraviolet censor and changes its colour when you have been too long time in the sun and must protect yourself. It can reduce the risk for the damage of the sun, says Alicja Lawrynowicz.

Material out to the market
Prototypes which now have been retrieved are not yet available in larger scale. So, what is going to happen with all discoveries?
The idea is that they are not going to stay in the laboratory. We hope that in the future our innovations will be used in industry, says Lawrynowicz.

The research is multidisciplinary, which means that there has been cooperation between different research groups. Research goes on also in other Nordic countries.  

Lupine can become textiles
In Denmark one research group has invested in ecofriendly colouring and created dyes out of big amounts of waste from local restaurants, among others avocado and onion peels. Avocado peels give textiles a beautiful yellow colour and onion creates brown nuances. In future these colours could replace traditional, toxic dyes.

At the same time researchers in Aalto University have produced textiles out of lupine, which is an invasive species in Finland.

Until now we have been removing lupines out of ditches and seeing it as a problem, but here researchers have created fibers and been able to weave a cloth out of it, says research coordinator Helen Salminen from the field of material science at the University of Turku.

Within the framework of the project researchers in Sweden have in turn worked on developing alternatives to plastic fibers (elastane) which are often used in jeans fabric for making fabric more elastic.

Cotton which contains a few percent of plastic fibers is difficult to recycle. This makes it difficult to use the fabric as a raw material for further processes. For that reason, it is important to find new ways to weave fabric so that fabric can be recycled and can be elastic without plastic fibers, says Alicja Lawrynowicz.

A single strand of fiber developed at Washington State University has the flexibility of cotton and the electric conductivity of a polymer, called polyaniline.

The newly developed material showed good potential for wearable e-textiles. The WSU researchers tested the fibers with a system that powered an LED light and another that sensed ammonia gas, detailing their findings in the journal Carbohydrate Polymers.

“We have one fiber in two sections: one section is the conventional cotton: flexible and strong enough for everyday use, and the other side is the conductive material,” said Hang Liu, WSU textile researcher and the study’s corresponding author. “The cotton can support the conductive material which can provide the needed function.”

While more development is needed, the idea is to integrate fibers like these into apparel as sensor patches with flexible circuits. These patches could be part of uniforms for firefighters, soldiers or workers who handle chemicals to detect for hazardous exposures. Other applications include health monitoring or exercise shirts that can do more than current fitness monitors.

“We have some smart wearables, like smart watches, that can track your movement and human vital signs, but we hope that in the future your everyday clothing can do these functions as well,” said Liu. “Fashion is not just color and style, as a lot of people think about it: fashion is science.”

In this study, the WSU team worked to overcome the challenges of mixing the conductive polymer with cotton cellulose. Polymers are substances with very large molecules that have repeating patterns. In this case, the researchers used polyaniline, also known as PANI, a synthetic polymer with conductive properties already used in applications such as printed circuit board manufacturing.

While intrinsically conductive, polyaniline is brittle and by itself, cannot be made into a fiber for textiles. To solve this, the WSU researchers dissolved cotton cellulose from recycled t-shirts into a solution and the conductive polymer into another separate solution. These two solutions were then merged together side-by-side, and the material was extruded to make one fiber.

The result showed good interfacial bonding, meaning the molecules from the different materials would stay together through stretching and bending.

Achieving the right mixture at the interface of cotton cellulose and polyaniline was a delicate balance, Liu said.

“We wanted these two solutions to work so that when the cotton and the conductive polymer contact each other they mix to a certain degree to kind of glue together, but we didn’t want them to mix too much, otherwise the conductivity would be reduced,” she said.

Additional WSU authors on this study included first author Wangcheng Liu as well as Zihui Zhao, Dan Liang, Wei-Hong Zhong and Jinwen Zhang. This research received support from the National Science Foundation and the Walmart Foundation Project.

For most people, the word "fashion" evokes thoughts of cuts, colors and patterns - but why not of live evaluations of vital functions or training sessions for rehabilitation patients? Up to now, products of the fashion industry have been largely analogous. The project Re-FREAM, however, was created to design smart clothes in the digital area. Here, researchers and artists work side by side, developing innovative and sustainable ideas and implementation options for the fashion industry, while simultaneously providing impulses for user-oriented synergies between textiles and technology.

The writer Maxim Gorki summed up the connection between two social spheres that were long believed to be irreconcilable: "Just as science is the intellect of the world, art is its soul". In the project Re-FREAM they are connected because fashion is not limited to the decision of the external, it is directly afflicted with sociological, technological and ecological world views. It is less and less sufficient to present only the beautiful, because the dark sides of the fashion industry must also be uncovered and countered with sustainable production cycles and fair working conditions. It is precisely this rethinking and redesigning of processes, production methods, but also of functionality and traditions in the world of fashion that is part of the Re-FREAM project.

The aim is to create an interaction between fashion, design, science and urban manufacturing in order to combine creative visions with sustainable technological solutions. In teams, artists and scientists developed projects together and then presented their innovative aesthetics at the virtual Ars Electronica Festival 2020.

The cooperation with Fraunhofer IZM's scientists opens up entirely new technological possibilities for artists: Microelectronics not only serves as a fashion accessory but is also brings new functions to clothing. With the help of integration technologies, clothing can be integrated into networks and textile-integrated sensor technology can be used, which opens up perspectives of wearable applications in the field of e-health.

One difficulty that Fraunhofer researchers are facing is the electronic contact points between electronics and textiles, because these must be manufacturable on an industrial scale and function reliably under typical textile mechanical stress and washing without any loss of performance. The electronic modules are a further challenge. At Fraunhofer IZM, the electronic components are miniaturized to such an extent that they do not stand out in the garment. The connecting conductor tracks are finally laminated or embroidered onto the fabrics.

Each sub-project in Re-FREAM is a unique joint effort, a fact that reflects the versatility of the cooperation partners. The Italian designer Giulia Tomasello, for example, wants to reveal taboos around female health in her project "Alma" and realize a monitoring of the vaginal flora. The team consisting of designers, an anthropologist and Fraunhofer researchers is developing underwear with an integrated pH sensor, designed to enable a non-invasive diagnosis of bacterial vaginosis and fungal diseases in everyday life and prevent serious inflammation.

In the gusset of the underwear, the reusable biosensor collects data and transmits them to a module measuring approximately 1 cm². Thanks to a modular design, the microcontroller can be easily removed from the textiles. The textile sensor, too, can be removed from the underwear. In addition to the technological solution, aesthetic requirements are another main focus. Other potential applications would be the monitoring of abnormal uterine bleeding as well as menopause. "Through close cooperation with the artists, we have gained very special insights into the user's perspective, and they in turn into that of application-oriented technologies. We have always challenged each other and have now found a solution that combines medical technology, wearables and a circular production method to empower women," says Max Marwede, who provided technical support for "Alma" at Fraunhofer IZM.

In the "Connextyle" project around designer and product developer Jessica Smarsch, the team also focuses on developing user-oriented garments: The tops, which are equipped with textile printed circuit boards and laminated EMG sensors, measure muscle activity and thus optimize rehabilitation processes for patients. An app provides visual feedback from the collected data, generates reports on the healing process and makes it easier for therapists to adapt the measures ideally.

Soft Robotics are the key point in the "Lovewear" project, because here inclusive underwear was developed, which is intended to help people with physical limitations in particular to explore their own intimacy and develop a greater awareness of their own body. Through interaction with a connected pillow, which functions as an interface, compressed air inserts are activated in the lace fabric. Instead of the commonly used silicon-based materials, Soft Robotics are made of textiles and thermoplastic materials. The researchers thus avoid the long curing process of silicone-based approaches and enable faster and more cost-effective mass production with available textile machines.

Particularly challenging and at the same time fruitful is the collaboration in creating sustainable and circular production designs in fashion. Ecological principles are taken into account at the design stage, minimizing negative environmental impacts throughout the product life cycle. This includes the reliability of the component contacts, the length of time the sensors adhere to the textile, the choice of materials and the modular design for reuse of the microcontrollers. However, the teams do not create individual pieces - they want to show that the path to high-tech fashion can also be an environmentally friendly one. They also worked on circular business models that fit the sustainable mission of the projects.

Thus Fraunhofer IZM’s expertise in the fields of e-textiles and circular design represents a considerable added value in the Re-FREAM project. With further investigations on suitable conductive materials, the researchers are currently developing sensory textiles and textile-suitable interconnection technologies. They are also working on thermoplastic substrates that can be integrated into almost any textile.

Re-FREAM is part of the STARTS (Science + Technology + Arts) program, which is funded as an initiative of the European Commission within the Horizon 2020 research and innovation program.