Textile materials change form when heated, providing designers with a plethora of new alternatives discovered by Aalto University. In addition to offering adjustable esthetics, 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 textiles combine ancient technology with a fresh perspective. LCEs (liquid crystalline elastomers) were invented in the 1980s. LCEs are a smart material that can react to heat, light, or other stimuli, and they’ve been employed in soft robotics as thin films. While LCEs have been converted into fibres, they have yet to be converted into textiles.
A team from Aalto’s Multifunctional Materials Design research group, directed by Prof. Jaana Vapaavuori, has now utilised LCE yarns to manufacture woven fabric using traditional textile crafting processes and examined how the fabric behaved in partnership with academics at the University of Cambridge. The research was published in Advanced Materials.
The team weaved LCE yarn in various patterns to create plain fabric, satin fabric, twill fabric, and a weft rib fabric. They created two copies of each design, one with soft LCE yarn and one with stiff LCE yarn, and then evaluated how the varied materials reacted to heat from an infrared light.
While the precise reaction varied from pattern to pattern, all of the LCE textiles constricted as they warmed up. The modifications were reversible—as the temperature decreased, the patterns loosened back to their original configuration.
“We weren’t sure what the effect of adopting industrial textile processes with these types of novel materials would be at first. The flexibility of the two forms of LCE yarn is similar to, if not softer than, spandex. It means it was critical to determine if the textile industry could employ these yarns and how their movement would be affected by their combination with conventional yarns “says Pedro Silva, the study’s lead author and a postdoctoral researcher at Aalto.
The team then woven a circle out of LCE yarns, linen, and nylon in a radial pattern to create a cone when heated. As the design was heated, the LCE yarn contracted, pushing the material up into a cone. The cone loosened back into a flat circle when it cooled.
This proof-of-concept advances the development of smart, reactive fabrics. “We accepted the challenge of collaborating with specialists from two distinct institutions from the start of this project. The study was successful and profited much from the multidisciplinarity, and the findings are now publicly accessible. We believe that our work will inspire new ways of thinking about tomorrow’s materials “Maija Vaara, an Aalto Ph.D. student who created the weaves and laces, explains.
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