Reviewed by Lexie CornerDec 9 2024
A group of scientists from Ohio State University developed a new shape-changing polymer that has the potential to revolutionize the construction of soft materials. The study was recently published in the journal Science.
The polymer is so adaptable that it can move in multiple directions. It is made of a substance known as Liquid Crystalline Elastomer (LCE), which is a soft substance that resembles rubber and can be stimulated by external forces like heat or light.
Study co-author Xiaoguang Wang, an Assistant Professor of Chemical and Biomolecular Engineering at Ohio State University, explains that the device can twist, tilt left and right, and shrink and expand, exhibiting behaviors similar to those of animals in the wild.
Liquid crystals are materials that have very unique characteristics and properties that other materials cannot normally achieve. They are fascinating to work with.
Xiaoguang Wang, Study Co-Author and Assistant Professor, Ohio State University
With its shape-changing capabilities, this new polymer could be used in the development of soft robots, artificial muscles, and other advanced medical and technological devices.
While liquid crystals are most commonly found in TVs and cell phone screens, their performance degrades over time. However, recent advances in LED technology have led many researchers to explore new applications for liquid crystals.
Unlike traditional materials, which can only bend in one direction or require multiple components to achieve complex shapes, this team's polymer is a single-component material that can twist in two directions. According to Wang, this unique property is linked to the way the material is heated, which controls the molecular phases of the polymer.
Liquid crystals have orientational order, meaning they can self-align. When we heat the LCE, they transition into different phases, causing a shift in their structure and properties.
Xiaoguang Wang, Study Co-Author and Assistant Professor, Ohio State University
This suggests that previously fixed molecules—tiny units of matter—can be reorganized in ways that enhance the material's flexibility. Wang notes that this feature may also simplify the material's manufacturing process.
If scaled up, the polymer used in this study could have significant potential in various scientific and technological fields, including biosensors, controlled drug delivery systems, and advanced locomotion techniques for next-generation soft robots.
Alan Weible, a co-author of the study and a graduate fellow in Chemical and Biomolecular Engineering at Ohio State, highlights one of the key findings of the research: the identification of the three stages the material undergoes as its temperature changes. During these stages, the molecules reorganize and self-assemble into different configurations.
“These phases are one of the key factors we optimized to allow the material am bidirectional shape deformability,” he said. The study also indicates that the material can be scaled to meet a wide range of size requirements.
“Our paper opens a new direction for people to start synthesizing other multiphase materials,” said Wang.
According to the researchers, with future advancements in computation, their polymer may eventually prove useful in handling delicate tasks, such as the precise design of artificial muscles and joints or enhancing soft nanorobots for complex surgeries.
In the next few years, we plan to develop new applications and hopefully break into the biomedical field. There is a lot more we can explore based on these results.
Alan Weible, Study Co-Author and Graduate Fellow, Ohio State University
The Department of Energy and the Harvard University Materials Research Science and Engineering Center funded the study.
Additional authors include Yuxing Yao, Shucong Li, Atalaya Milan Wilborn, Friedrich Stricker, Joanna Aizenberg, Baptiste Lemaire, Robert K. A. Bennett, Tung Chun Cheung and Alison Grinthal from Harvard University; Foteini Trigka and Michael M. Lerch from the University of Groningen; Guillaume Freychet, Mikhail Zhernenkov and Patryk Wasik from Brookhaven National Laboratory; and Boris Kozinsky from Bosch Research.
Journal Reference:
Yao, Y., et al. (2024) Programming liquid crystal elastomers for multistep ambidirectional deformability. Science. doi.org/10.1126/science.adq6434.