The breakthrough composite material combines flexibility and strength for advanced robotic applications

The field of robotics has transformed drastically in this century, with a special focus on soft robotics. In this context, origami-inspired deployable structures with compact storage and efficient deployment features have gained prominence in aerospace, architecture, and medical fields. Thus far, experts have mainly utilized paper, thin glass, and polymers as foldable materials for such applications. However, fiber-reinforced polymer (FRP)—a state-of-the-art alternative—remains underexplored in terms of the accuracy and reliability of the fabrication process.

Addressing this knowledge gap, a team of scientists from Pusan National University, led by Dong Gi Seong, an associate professor in the Department of Polymer Science and Engineering, has proposed a multi-resin dispensing process for FRP fabrication that combines rigid and flexible epoxy resins, allowing for the precise patterning of mechanical properties within a monolithic structure. Their work was made available online on 30 June 2025 and has been published in Volume 305 of Composites Part B: Engineering journal on 1 October 2025.

Dr. Seong highlights the main contribution of their work, stating, "Our novel and efficient technique for fabricating composite materials that enable flexible bending while maintaining strong structural performance—an advancement that has not been previously reported in the literature—overcomes the limitations of traditional single-resin systems and manual processes, enabling selective control of rigidity and flexibility within the monolithic composite."

In this way, the researchers achieve flexible bending without compromising the structural integrity required for advanced deployable structures in various applications including rigid-soft robotics applications. They demonstrate the potential of their approach to produce durable, high-performance FRP composites through the successful fabrication of a triangulated cylindrical origami structure.

These composites exhibit a flexural modulus of 6.95 GPa in rigid sections and 0.66 GPa in foldable sections, with a bending radius of less than 0.5 mm, ensuring both flexibility and stability under repetitive cycles with high strain tolerance. Furthermore, the fabricated structure is lightweight, mechanically robust, and capable of complex motions such as extension, compression, bending, twisting, and deployment, making it ideal for a wide range of applications.

According to Dr. Seong, their innovation can lead to significant breakthroughs in various futuristic fields of science and technology. "Its applications include robotic parts including joints to create a Transformer-like robot, deployable parts for space applications such as deployable solar panel and solar sailing spacecraft, foldable and rollable electronics substrate or cover, architectural designs for tent, military or emergency shelter, as well as transformable wheel for next-gen vehicles."

This research lays the groundwork for compactly stored structures that can be precisely deployed and retain their mechanical durability, leading to long-term societal impacts, including but not limited to enhanced reliability of emergency tents and wearable protective equipment for disaster response and improved transportation efficiency for low Earth orbit satellite systems, accelerating the global rollout of space-based internet.

In the long term, the proposed technology can pave the way for applications in robotics where unified rigid-soft structures can enable power suits, humanoid joints, and adaptive electronics, as well as guide viable material choice for transformable wheels and adaptive structure, enabling energy-efficient mobility systems compared to heavier metal components.

Ultimately, this work could serve as the foundation for next-generation technologies that demand both deployability and durability in everyday life.

Reference
Title of original paper: Deployable fiber-reinforced polymer for advanced monolithic Rigid-Soft robotics applications
Journal: Composites Part B: Engineering
DOI: 10.1016/j.compositesb.2025.112754

About Pusan National University
Website: https://www.pusan.ac.kr/eng/Main.do