Wed. Dec 6th, 2023
    Exploring the Limitations of Soft Robotics: Unveiling Weaknesses in Morphing Cones

    Soft robotics, a field in which components are designed to be deformable and flexible, has been revolutionizing mechanical tasks with its innovative use of soft elements and actuators. However, new research conducted by engineers at the University of Cambridge has brought to light performance-limiting weaknesses in conical shells made from soft materials, which could have implications for the future of soft robotics.

    The engineers focused their study on conical liquid crystal elastomer (LCE) shells, a lightweight shape-morphing material widely used in soft robotics. By employing a combination of theory, numerics, and experiments, they aimed to determine the load-bearing capacity of these thin LCE films.

    Their findings, published in the journal Physical Review Letters, shed light on both the strength and weaknesses of these conical structures. While the ability of the LCE shells to lift thousands of times their weight showcases their remarkable strength, the researchers also discovered an unexpected vulnerability when the cones are compressed.

    Unlike flat LCE sheets that morph into cones and exhibit considerable strength, the researchers found that the thin-walled cones deform predominantly in the outer boundary layer when compressed. This deformation triggers buckling at significantly lower loads than previously predicted, highlighting a critical weakness in their performance.

    Daniel Duffy, a co-author of the study and PhD student in the Department of Engineering at the University of Cambridge, emphasizes the broader implications of their findings, stating, “Our work reveals some key underlying principles that we expect to apply beyond just cones. We have uncovered how free unclamped edges can substantially weaken thin structures, impacting various mechanisms unrelated to soft robotics.”

    As soft robotics continues to advance, these findings prompt designers and engineers to reevaluate the strength and limitations of shape-morphing cones as powerful actuators. Moreover, the study’s exploration of weakened structures extends beyond soft robotics, potentially influencing the design and optimization of various mechanical systems.


    What are soft robotics?

    Soft robotics is a field that focuses on designing components and mechanisms that are deformable, flexible, and made from soft materials. These soft elements are used to construct robots that can perform mechanical tasks in a wide range of applications.

    What are LCE shells?

    LCE shells refer to conical structures made from liquid crystal elastomers, which are lightweight materials capable of shape-morphing. LCE shells have been widely used in soft robotics due to their flexibility and deformable properties.

    What did the researchers discover?

    The researchers found that while thin LCE cones exhibit remarkable strength when lifting heavy loads, they possess a weakness when compressed. The outer boundary layer of these cones deforms under compression, leading to buckling at much lower loads than previously predicted.

    What are the broader implications of the study?

    The study’s findings extend beyond soft robotics, revealing underlying principles that can weaken thin structures in various mechanical systems. The discovery of how free unclamped edges impact the strength of these structures has implications for design optimization beyond the realm of soft robotics.