Textination Newsline

Researchers have trained an artificial intelligence to design the structure of so-called metamaterials with desired mechanical properties for a wide range of applications.

• ETH researchers have used artificial intelligence to design metamaterials that show unusual or extraordinary responses to complex loads.
• Their new AI tool deciphers the essential features of a metamaterial’s microstructure and accurately predicts its deformation behaviour.
• The tool not only finds optimal microstructures but also bypasses time-consuming engineering simulations.

Bike helmets that absorb the energy of an impact, running shoes that give you an extra boost with every step, or implants that behave just like natural bone. Metamaterials make such applications possible. Their inner structure is the result of a careful design process, following which 3D printers produce structures with optimised properties. Researchers led by Dennis Kochmann, Professor of Mechanics and Materials in the Department of Mechanical and Process Engineering at ETH Zurich, have developed novel AI tools that bypass the time-consuming and intuition-based design process of metamaterials. Instead, they predict metamaterials with extraordinary properties in a rapid and automated fashion. A novelty, their framework applies to large (so-called non-linear) loads, e.g. when a helmet absorbs major forces during an impact.

Kochmann’s team has been among the pioneers in designing small-scale cellular structures (similar to beam networks in timber-frame houses) to create metamaterials with specific or extreme properties. “For example, we design metamaterials that behave like fluids: hard to compress but easy to deform. Or metamaterials that shrink in all directions when compressed in a particular one,” explains Kochmann.

Efficient, optimal material design
The design possibilities seem endless. However, the full potential of metamaterials is far from realised, since the design process is based on experience, involving trial and error. Furthermore, small changes in the structure can give rise to huge changes in properties.

In their recent breakthrough, the researchers succeeded in using AI to systematically explore the abundant design and mechanical properties of two types of metamaterials. Their computational tools can predict optimal structures for desired deformation responses at the push of a button. Key is the use of large datasets of the deformation behaviour of real structures to train an AI model that not only reproduces data but also generates and optimises new structures. By leveraging a method known as “variational autoencoders”, the AI learns the essential features of a structure from the large set of design parameters and how they result in specific properties. It then uses this knowledge to generate a metamaterial blueprint whenever the researchers specify its desired properties and requirements.

Assembling building blocks
Li Zheng, a doctoral student in Kochmann’s group, trained an AI model using a dataset of one million structures and their simulated response. “Imagine a huge box of Lego bricks – you can arrange them in countless ways and over time learn design principles. The AI does this extremely efficiently and learns essential design features and how to assemble the building blocks of metamaterials to give them a particular softness or hardness”, says Zheng. Unlike prior approaches using a small catalogue of building blocks as the basis for design, the new method gives the AI freedom to add, remove, or move building blocks around almost arbitrarily.  Together with Sid Kumar, an assistant professor at TU Delft and a former member of Kochmann’s team, they showed in a recently published paper that the AI model can even go beyond what it has been trained to do and predict structures that are far better than anything ever generated before.

Learning from the movies
Jan-Hendrik Bastek, also doctoral student in Kochmann’s group, used a different approach to achieve something similar. He used a method originally introduced for AI-based video generation, which has become commonplace: if you type in ‘an elephant flying over Zurich’, the AI generates a realistic video of an elephant circling the Fraumünster Church. Bastek trained his AI system using 50,000 video sequences of deforming 3D-printable structures. “I can insert the trajectory of how I want the structures to deform, and the AI produces a video of the optimal structure and the complete deformation response,” explains Bastek. Most previous approaches have focused on only predicting a single image of the optimal structure. However, giving the AI videos of the entire deformation process is crucial to retain accuracy in such complex scenarios. Based on the video sequences, the AI can create blueprints for new materials, taking into account highly complex scenarios.

Big benefits for bike helmets and shoe soles
The researchers have made available their AI tools to the metamaterials community. This will hopefully lead to the design of many new and unusual materials. The tools are opening new avenues for the development of protective equipment such as bicycle helmets and for further applications of metamaterials from medical engineering to soft robotics. Even shoe soles can be designed to absorb shocks better when running or to provide a forward boost when stepping down. Will AI completely replace the manual engineering design of materials? “No,” laughs Kochmann. “Used well, AI can be a highly efficient and diligent assistant, but it must be given the right instructions and the right training – and that requires scientific principles and engineering knowhow.”

• Clothing exports stagnate
• Shoe production becomes more important
• Investment in modern technology necessary

Bonn (GTAI) - The Indonesian textile industry faces strong regional competition. Since their demand for machinery and clothing exports peaked about five years ago, the industry's exports have stagnated. Nevertheless, the archipelago is important for international market participants at least as a second location alongside the major producing countries. In the meantime, the country has developed into an important shoe manufacturer and is further expanding its production capacities.

Indonesia is one of the top 15 clothing exporters. Over the past decades, the archipelago has continuously increased its production and thus created a growing demand for textile machinery. But the market has been stagnating for five years: exports are at around USD 7.5 billion per year, and imports of textile machinery have fallen from USD 1 billion per year to only around 800 million US dollars.

The most important supplier of textile machinery is the PR China, which has expanded its import share to around 30 percent in recent years and displaced Japan from first place. According to Indonesian import statistics, the German delivery ratio fluctuates by 10 percent.

The Indonesian textile association API cites the lower demand for clothing, especially from the USA and Europe, as the reason for the weak export development. About half of industry exports goes to North America. The largest customers are Japan, Germany, South Korea and the United Kingdom. What the association does not say: Bangladesh, Vietnam, India, Cambodia and Myanmar have all significantly increased their clothing exports in the past five years.

*) SITC 724
Source: UN Comtrade

Shorter production cycles
Indonesia's textile companies must therefore invest in order to remain competitive. Even though, according to API, more than half of the member companies are already technologically advanced, many market participants still have an outdated machinery. And especially against the background of fiercer competitive conditions, this is a decisive disadvantage. According to the association, larger fashion chains insist on ever shorter delivery times. Where the producers used to have three months, today it is only three weeks.

Regional competition is also a problem for manufacturers. The archipelago has good conditions for a labor-intensive industry such as the textile industry. Wages are low - outside the conurbations - and the labor supply is inexhaustible (also because many men work as sewers in the factories). Nevertheless, the country has not yet managed to become serious competition for the main export countries of cheap mass-produced goods.

*) SITC 724
Source: UN Comtrade

The archipelago also has locational disadvantages: it is further away from the European sales markets than other manufacturing countries and has a greater distance to China also, which, due to the high wage increases, is increasingly relocating its clothing production to its immediate neighbors. Moreover, in Indonesia, which is comparatively wealthy due to its large raw material exports, the minimum wages of India, Cambodia, Bangladesh or Myanmar cannot be undercut.

1) SITC 84; 2) Mirror statistics of partner countries
Source: UN Comtrade

Investments at previous year's level
After all, Indonesia has managed to become an important second location for international apparel companies, mitigating risks in major manufacturing countries. Most of the manufacturers are located in populous Java. For the government, further expansion of the industry is important in order to bring the large number of unskilled workers to work.

According to the latest available data from the Federal Statistical Office (BPS), the number of employees in the roughly 2,600 medium and large companies in the sector has increased from 470,000 (2008) to 550,000 (2014). In addition, there are just under 210,000 workers in small and micro companies (2015), most of whom are one- or two-person businesses.

The BKPM investment agency reports FDI of USD 184 million for the first half of 2017 for 494 projects. This corresponds almost exactly to the sum of the same period of the previous year. For the full year of 2016, USD 321 million of FDI had flowed into the sector.

Shoe manufacturers expand capacities
The domestic footwear industry is developing far more dynamically than the textile industry. Indonesia has become the third most important exporter in terms of cheap mass production in a few years, but it is far behind China and Vietnam. After all, the corresponding exports between 2011 and 2016 have steadily increased from USD 3.3 billion to USD 4.6 billion.

1) SITC 82; 2) General Statistics Office of Vietnam
Source: UN Comtrade

And the signs are still on expansion: In the first six months of 2017, the leather and footwear sector had FDI of USD 187 million, a third more than in the total year 2016. Domestic market participants are also expanding. The Indonesian manufacturer SCI is currently building a new production facility in the central Javanese Salatiga, near the port city of Semarang. It should be completed in October. In the first phase 300,000 to 500,000 pairs of shoes per year could be produced, the maximum capacity is 1 million pairs.
 

Paint, glitter and metallic effects should provide the highlights at the foot in the coming autumn / winter 2016/2017. In addition, deep shades of red and the trend color cognac and camel. Otherwise it is said: more volume, more profile. Androgenic shoe types conquer the shoe racks.

While the chilly autumn weather in September and in the first half of October still brought good sales for winter shoes and boots, the mild November and December thwart the retailers bill. Especially snow shoes and boots became shop keepers at many places, especially small and medium size enterprises had to record a decline in sales. Although the online trade had to fight with the same weather conditions, initial figures however indicate, that the online shoe trade was able to register last year a sales growth of around seven percent. The stationary trade is looking for new concepts, is even more intensely dealing with its assortments and suppliers and aims to react therefore with a proper weighting of new footwear trends. Many traders took advantage of the just ended GDS shoe fair in Dusseldorf in order to learn about the new trends for autumn / winter 2016/17: The hippie look with its inspirations from the 1970s finds its continuation. Folkloric elements are implemented with much attention to details: fringe, fur, embroidery and patchwork will be found not only on shoes but on boots as well. Velvets, animal prints, tapestry, floral or abstract patterns enhance the detail-note of the theme. Snake prints are found not only subtly used as an ornament, but all over the entire shoe. Pumps and ballerinas are interpreted feminine with curved heels. Hip, although probably not a bringer of numbers, the overknee, to be carried with the tunic dress.

Trendy remain androgynous types of footwear such as Budapest, Broques, Monks and Loafer, that are perfectly suited to types of trousers as the culotte and the new over long pants. Their soles are partly very distinctive but extremely light. Loving details such as perforations, tassels, straps ensure modernity. The new bootees convince thru reduced optics and different shaft heights: They range from almost ankledeep over classic variants to medium-high boots which are worn narrow to the leg. Copped and round boot strips stay, new are square forms. At heels block-heels and slightly tapered shapes are in vogue, the soles are ultra-light and come in their fashionable variants as plateau or wedge soles.

The sneaker is an indispensable part of the shoe closets and remains unbeatable in the coming autumn / winter. In the new season it will appear cleaner and with fewer details. Tone in tone leo, metallics and suede will be mixed with a little paint, which gives the new sneakers an extravagant touch. Matt-gloss and 3D effects give the sneakers a high fashion look. For the colder months the sneaker comes in a material mix with fur and a warm interior design. Neoprene, mesh and leather produce in combination with 3D printing a new trendy image. Side zipper, damping and padding ensure greater comfort. For the soles lightweight, flexible PU or mix variants remain important. Fashionably are darker soles or soles in a dirty look in addition to the white and light soils.

In the new season the classic black and will not disappear from the shoe cabinets, even though black will not be traded as the ultimate trend color in the new season. Buying impulses should be given by stone, timber and mineral tones as well as cognac and camel, rust and deep shades of red and khaki, olive and denim tones. Color gradients and strong contrasts create a new appearance. Gloss and glitter are back in the trend, through glittering colors as well as through pearls and strass.

The choice of materials by the designers for the new shoe fashion is versatile as seldom before, they like to mix in the new season: animated, soft qualities with haptic and structure, next to very clean, smooth qualities. It will be patched, stitched, printed, embossed, patterned and flocked. The trendy shoe materials include leather qualities in natural optics, often with noticeable grain pattern. Lizard embossments are back in vogue, especially crocodile and python. Soft suede and nubuck qualities are a must. Exceptional finish effects and fantasy embossments are very trendy. 3D is not just an issue for new high-tech qualities,
but can also be seen as brocade, bouclé, lace or jacquard pattern.