A team of engineers at UCLA has created an innovative type of tunable dynamic material, drawing inspiration from the inner mechanics of push puppet toys. These popular toys, which can stand or collapse with the push of a button, served as the blueprint for a new metamaterial with exciting potential applications in soft robotics, reconfigurable structures, and space engineering.

Figure 1. The Proposed Method. (Credit: Wenzhong Yan/UCLA)

The principle behind push puppet toys lies in the tension of connecting cords: when pulled tight, the toy stands firm, but when loosened, it collapses. UCLA researchers applied this tension-based concept to develop a groundbreaking lightweight metamaterial [1]. This material features motor-driven or self-actuating cords threaded through interlocking cone-tipped beads. When the cords are tightened, the beads align and lock into place, causing the material to stiffen while maintaining its structural integrity [2]. Figure 1 shows the undeployed metamaterial (left) gains strength and form when deployed (center), with the ability to return to its limp state (right).

The study, published in Materials Horizons, highlights the metamaterial’s versatile properties that could lead to its integration into a range of advanced applications:

• The material’s stiffness can be finely tuned by adjusting the tension in the cords. At full tension, the structure reaches maximum stiffness, but gradual adjustments allow for flexibility while still maintaining strength.
• The material can repeatedly collapse and stiffen, making it ideal for long-lasting designs that require frequent reconfiguration. It also becomes compact and easy to transport when not deployed.
• After deployment, the material becomes over 35 times stiffer and exhibits a 50% change in damping capability, demonstrating its remarkable tunability.
• The metamaterial could be designed for self-actuation, enabling structures to change shape autonomously without human intervention.

“Our metamaterial enables new capabilities, showing great potential for its incorporation into robotics, reconfigurable structures and space engineering,” said Wenzhong Yan, corresponding author and UCLA Samueli School of Engineering postdoctoral scholar.

The research team, including senior authors Ankur Mehta and Jonathan Hopkins, envisions the material’s use in a variety of fields, such as self-deployable soft robots capable of adapting their stiffness to different terrains, or in reconfigurable shelters and shock absorbers with customizable damping properties.

Looking forward, the researchers see vast possibilities in further tailoring the material’s capabilities by altering the size, shape, and connectivity of the beads.

The study was supported by the Office of Naval Research, DARPA, and the Air Force Office of Scientific Research, with additional resources from UCLA’s Office of Advanced Research Computing.

Source: University of California - Los Angeles

References:

1. https://www.sciencedaily.com/releases/2024/08/240812165449.htm
2. https://www.eurekalert.org/news-releases/1054367

Cite this article:

Hana M (2024), UCLA Engineers Develop Revolutionary Dynamic Material Inspired by Push Puppet Toys, AnaTechMaz, pp. 44