Smart fabrics respond to changes in temperature

New textiles developed at Aalto University change shape when they heat up, giving designers a wide range of new options. In addition to offering adjustable aesthetics, responsive smart fabrics could also help monitor people’s health, improve thermal insulation, and provide new tools for managing room acoustics and interior design.

The new fabrics weave together old technology and a new approach. Liquid crystalline elastomers (LCEs) were developed in the 1980s. LCEs are a smart material that can respond to heat, light, or other stimuli, and they’ve been used as thin films in soft robotics.

In collaboration with researchers at the University of Cambridge, a team from the research group at Aalto led by Professor Jaana Vapaavuori has now woven fabrics out of LCE yarns using conventional textile crafting techniques and tested how they behave.

The team wove LCE yarn in different patterns to make plain fabric, satin, twill, and a weft rib fabric. They made two versions of each pattern using either a soft or stiff LCE yarn, and then they tested how the different fabrics responded to heat from an infrared lamp.

All of the LCE fabrics contracted as they warmed up, though the exact response differed from pattern to pattern. The changes were reversible –the patterns relaxed back to their original shape as their temperature dropped.

Next, the team combined LCE yarns with linen and nylon in a radial pattern to weave a circle that would lift itself into a cone when heated. Heating the pattern caused the LCE yarn to contract, pulling the cloth up into a cone. As it cooled, the cone relaxed back into a flat circle.

Parliament Sampo sheds light on political debates

Researchers from Aalto University and the University of Helsinki have developed an open data service that contains nearly one million speeches held in the Finnish Parliament since 1907. The entire dataset has been compiled into a semantic web.

For example, Parliament Sampo can show who has mostly frequently interrupted other MPs or what the representatives from different parties have been speaking about.

Parliamentary speeches were digitised and available before Parliament Sampo, but studying the entire corpus was a laborious manual task and lacked the benefits of automation

While the traditional web works with links between webpages, the semantic web works by linking data between webpages, explains Eero Hyvönen, Professor of Computer Science.

‘Data in the semantic web can be enriched with information from several different sources, which a machine can use to associate individual words to larger contexts and offer it to the user.’ parlamenttisampo.fi

Hyvönen leads the semantic computing research group, which has been developing various Sampo services for years with the aim of providing essential national data sets to researchers and citizens. A prominent example is War Sampo, which has already been used by more than a million people.

Crop yields reduced by climate extremes

From 1980 to 2009, farmers faced an ever-increasing chance of having to deal with a growing season that was too hot and dry for their crops, according to a new study from an international team led by researchers at Aalto University. Wheat growers saw the biggest change, with the chance of extreme heat and drought during the growing season increasing sixfold over the study period. The risk for maize, rice, and soybean doubled – a smaller increase, but nevertheless considerable. The researchers also investigated the effect of these conditions on crop yields. Their model showed that heat and drought reduced wheat yields by about 4% overall, though some regions saw much greater reductions, notably parts of Russia and China, both major global producers. Likewise, maize yields were about 3% lower because of hot and dry weather, but the losses were more severe in areas of North America, Eastern Europe and China.

‘As the threat of weather extremes