Material with novel stretching properties developed
Metamaterials are artificially engineered materials that do not occur in nature. Their building blocks function like atoms in conventional materials but have special optical, electrical, or magnetic properties. The key to their functionality lies in the interaction between the building blocks: until now, these interactions were mostly possible only with directly adjacent building blocks, i.e., locally. Researchers at the Karlsruhe Institute of Technology (KIT) have developed a mechanical metamaterial that allows these interactions to be triggered over greater distances within the material. The material could be used for applications such as force measurement or structural monitoring. The results have been published in the journal Nature Communications. (Source: Karlsruhe Institute of Technology – Press Releases)
The research group led by Professor Martin Wegener at the Institute of Applied Physics (APH) at KIT has thus succeeded in overcoming a limitation in metamaterials. Lead author Dr. Yi Chen compares this to human communication and an effect familiar from the game “Chinese whispers”: when communicating with someone through an intermediary, the final outcome can be completely different from direct communication with that person. This principle also applies to metamaterials, says Chen. “The material we designed has special structures (shown in red in the figure). These allow individual building blocks not only to ‘communicate’ with their neighbors but also directly with all other building blocks in the material,” explains the scientist.
Experiments on 3D-printed microscopic samples
“These structures grant the material fascinating properties, such as unusual stretching behavior,” reports co-author Ke Wang from APH. The team demonstrated this in micrometer-sized material samples, which they produced using 3D laser printing technology, examined under a microscope, and recorded with a camera. It was observed that a one-dimensional strand (1D), pulled from one end, did not stretch uniformly.
Unlike a rubber band, which stretches evenly under tension, the metamaterial showed compressions in certain areas. Additionally, shorter sections of the metamaterial stretched more than longer sections, even when the same force was applied throughout. “This unusual behavior, where individual stretches and compressions occur only locally, is not possible in conventional materials,” says Jonathan Schneider from APH, another co-author. “We will now investigate this in two-dimensional (plate-like) materials and three-dimensional materials.”
Another potentially useful property of the metamaterial could be its high sensitivity to applied loads. Depending on the point of force application, this can lead to completely different stretching responses even at distant points. In contrast, conventional materials show reactions only directly at the point of force application, with weak or negligible effects observed elsewhere in the material. A material with such sensitivity could be valuable for applications requiring large-scale force measurement, such as monitoring building deformations in civil engineering or characterizing cellular forces in biological research.
The research was supported by the Excellence Cluster 3D Matter Made to Order (3DMM2O) of KIT and Heidelberg University.
KIT/A. Karbe, 24.10.2024
Note: The article has been translated from German to English. It is based on a press release from KIT.
The original press release can be found at:
Material mit neuartigen Dehnungseigenschaften entwickelt (only in german)
The original publication can be found at (Open Access):
Yi Chen, Jonathan L.G. Schneider, Ke Wang, Philip Scott, Sebastian Kalt, Muamer Kadic, Martin Wegener: Anomalous frozen evanescent phonons, Nature Communications, 2024. DOI: 10.1038/s41467-024-52956-5
Localization in Helmholtz Information:
Helmholtz Information, Program 3: Materials Systems Engineering, Topic 2: Optics & Photonics: Materials, Devices, and Systems
Contact:
Prof. Dr. Martin Wegener
Institute of Applied Physics
Karlsruhe Institute of Technology (KIT)
Phone: +49 721 608-43401
E-Mail: martin.wegener@kit.edu
Contact for this press release:
Antje Karbe
Press Officer
Karlsruhe Institute of Technology (KIT)
Phone: +49 721-608-41186
E-Mail: antje.karbe@kit.edu
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