In a groundbreaking advancement at the intersection of materials science, robotics, and biomedical engineering, researchers at North Carolina State University have pioneered an innovative 3D printing technique capable of producing ultra-thin “magnetic muscles.” These films, meticulously engineered by co-extruding rubber polymers with ferromagnetic particles, can be seamlessly integrated with origami-inspired soft robots, enabling precise and controllable motion driven solely by external magnetic fields. This development promises to revolutionize soft robotics, providing untethered actuation with unprecedented flexibility and minimal spatial footprint.
Traditional magnetic actuators have long relied on embedding rigid magnets onto the surface of soft robotic systems, an approach that invariably compromises the surface area and the robot’s overall flexibility. Contrastingly, the novel method developed by lead author Xiaomeng Fang and her team leverages a thin magnetic elastomer film directly printed onto the critical segments of origami robots. By dramatically reducing the bulk introduced by conventional magnets, this paradigm allows the robots to retain their essential folding dynamics without hindrance, essentially acting as artificial muscles that breathe life into meticulously folded paper-like structures.
Central to this innovation is the adaptation of the Miura-Ori origami fold, a pattern renowned for its remarkable ability to transform large flat sheets into compact forms without destroying the geometry. By applying the soft magnetic films to specific facets of these Miura-Ori patterns, the researchers created robots capable of controlled expansion and contraction when subjected to external magnetic fields. Crucially, the “magnetic muscles” do not act as passive joints but actively impart force, facilitating complex motions reminiscent of biological systems and enabling robots to adaptively interact with their environment.
One of the flagship prototypes is a medically oriented soft robot engineered to deliver medication non-invasively to ulcers within the human gastrointestinal tract. Mimicking a miniaturized origami capsule, this device, upon ingestion, remains folded for passage through the digestive system. Upon reaching the targeted location, external magnetic guidance triggers the magnetic muscles to unfold the structure, securing the robot in place for controlled drug release. This approach circumvents the invasiveness of conventional endoscopic procedures, allowing patients to continue daily routines without disruption, marking a significant milestone in personalized medicine.
The fabrication process of these magnetic films posed substantial challenges due to the dual need for flexibility and magnetic responsiveness. Conventional exposures of polymeric magnetoactive inks to ultraviolet light proved insufficient for curing when these inks contained high concentrations of ferromagnetic particles. The pigmentation and density of the ferromagnetic inclusions attenuated UV penetration, impairing the crosslinking process essential for solidifying the elastomer matrix. Addressing this, the research team ingeniously combined UV curing with a thermally heated collecting platform, ensuring rapid and thorough curing even in densely loaded magnetic composites, a crucial breakthrough enabling up to 75 weight percent particle loading.
High loading of ferromagnetic particles correlates directly with enhanced magnetic force generation, a key factor in achieving potent actuation. The synergy between the dual curing mechanism and material composition facilitated the creation of films that maintained flexibility while delivering powerful, programmable magnetic responses. These films can be precisely patterned during printing, granting the ability to tailor the magnetic polarity and distribution to optimize actuation mechanics depending on the robot’s intended function and environment.
Beyond the realm of drug delivery, the researchers designed a second origami robot exhibiting crawling locomotion, reminiscent of biological organisms such as inchworms. Equipped with strategically placed magnetic muscles, this crawler contracts and expands in response to alternating magnetic fields, stepping forward incrementally. Notably, it demonstrated the ability to traverse obstacles up to 7 millimeters high and adapt to uneven terrain, including granular substrates like sand. The speed and gait modulation are finely tunable through magnetic field strength and frequency adjustments, showcasing an elegant model of soft robotic mobility.
The integration of soft magnetoactive materials and origami architectures opens fertile ground for multifaceted applications. From biomedicine to space exploration, these lightweight, wireless, and scalable actuators offer unparalleled adaptability. Aerial drones, space deployable antennas, and other complex systems prone to environmental constraints or requiring compact stowage might benefit from these innovations. The modularity inherent in origami designs complements the dynamic nature of soft actuators, potentially ushering in a new era of robotics where form and function co-evolve seamlessly.
Furthermore, the study paves the way for robots that are not only physically compliant but also possess programmable mechanical intelligence by harnessing magnetic fields. Unlike pneumatic or cable-driven actuators, these magnetic muscles afford rapid response times and wireless control without the encumbrance of bulky power supplies or tethered connections. This enables the development of minimally invasive devices operating in constrained or inaccessible environments, including inside living organisms.
The researchers verified the drug delivery robot’s performance using a mock stomach model—a plastic sphere filled with warm water, simulating human physiological conditions. By maneuvering the robot magnetically to a designated ulcer site and then actuating its unfolding mechanism, they demonstrated precise navigation and retention capabilities. The robot’s secure fixation via supplementary soft magnetic films enhances drug delivery stability, ensuring sustained, controlled release, a vital attribute for therapeutic efficacy and patient safety.
Soft robotics is a swiftly advancing field characterized by the pursuit of materials and designs that inherently coexist with delicate biological tissues and complex environments. This research embodies that spirit by marrying the ancient art of origami with cutting-edge magnetoactive materials and advanced 3D printing technologies. The result is a platform that is not only asynchronous with traditional rigid robotics but also heralds transformative approaches to actuation, control, and application.
The team emphasizes the untapped potential still residing in origami-inspired structures combined with soft magnetic films. The variation in fold patterns, actuator placement, and programmable magnetic directions is vast, suggesting a rich landscape for future innovations. Efforts to scale the technology for larger or smaller constructs, introduce sensing capabilities, and explore alternative magnetic materials and composites are logical next steps. These directions could fuel a new wave of responsive robots that autonomously adapt to complex tasks ranging from surgical assistance to exploration missions on extraterrestrial terrains.
In sum, this study illustrates an elegant marriage of materials science, mechanical engineering, and robotics, leveraging the unique properties of 3D-printed soft magnetoactive films and origami structures to forge versatile soft actuators. The promising prototypes—a drug delivery system and a terrain-adaptive crawler—signal the vast horizons for such technology. As external magnetic control permits wireless direction and power, these robots epitomize a new class of multifunctional, scalable, and embedded actuation systems poised to fundamentally alter how we imagine robotic movement and interaction in constrained spaces.
Subject of Research:
Soft magnetoactive materials integrated with origami structures for advanced soft robotics applications.
Article Title:
3D-Printed Soft Magnetoactive Origami Actuators
News Publication Date:
September 12, 2025
Web References:
https://advanced.onlinelibrary.wiley.com/doi/10.1002/adfm.202516404
References:
Xiaomeng Fang, Sen Zhang, Yuan Li, Zimeng Li, Nabil Chedid, Peiqi Zhang, and Ke Cheng. “3D-Printed Soft Magnetoactive Origami Actuators.” Advanced Functional Materials, 2025.
Image Credits:
North Carolina State University
Keywords:
Soft robotics, magnetic actuators, 3D printing, origami structures, magnetoactive materials, biomedical robots, drug delivery, soft elastomers, ferromagnetic particles, Miura-Ori fold, wireless actuation, terrain adaptive robots
