Magnetic composite with stiffness control allows programmable 3D shape shifting for use in soft robots, tactile interfaces, and reconfigurable displays.
(Nanowerk Spotlight) Cephalopods such as cuttlefish and octopuses adjust the texture of their skin by raising or flattening small muscle-controlled structures known as papillae. These changes in surface morphology occur rapidly and reversibly, enabling camouflage, signaling, or reduced drag during movement. Scientists have long viewed these animals as models for synthetic materials that could dynamically change shape. But engineering a system that can reliably shift between multiple complex 3D configurations—without permanent mechanical deformation, slow response, or limited form—is a persistent challenge in the field of soft robotics and adaptive interfaces.
Numerous materials have been studied for their ability to undergo shape changes in response to external stimuli. Shape memory polymers, liquid crystal elastomers, dielectric actuators, and responsive hydrogels can each transition from two-dimensional to three-dimensional forms. However, these systems often offer only a narrow set of reversible shapes, typically limited to simple bends, folds, or domes. Some rely on pre-defined structural patterns—like the folds in origami—that restrict versatility. Others exhibit slow recovery times or degrade mechanically over repeated cycles. Attempts to use magnetic composites have expanded shape control to a degree, but most designs still produce only single-function transformations or lack the mechanical rigidity needed for functional deployment.
In response to these constraints, researchers from the Korea Advanced Institute of Science and Technology and Pohang University of Science and Technology have developed a reconfigurable material system inspired by the muscular skin of cephalopods. Their approach combines thermal control and magnetic programming in a structure they call a Magnetic Morphing Platform (MMP). This composite system enables multiple, repeatable shape transitions between a flat and a wide range of complex three-dimensional geometries. What distinguishes it from prior systems is its simultaneous stiffness-tuning, memory retention, and the ability to reprogram its response to magnetic fields on demand.
Concept and operational principle of cephalopod-inspired programmable 3D shape transformation using MMP. a) Schematic diagram illustrating the dynamic 3D skin texture morphing mechanism of cephalopods (i.e., sepia officinalis) using their skin papillae for camouflage. The cephalopod can reversibly create intricate 3D papillae by erection and contraction of muscle fibers with multiple muscular hydrostats from the smooth skin surface. b) Photographic demonstration of bioinspired 3D magnetic shape-morphing featuring consecutive shape programmability and fixation through magnetic and thermal stimuli. Our proposed strategy inspired by the inherent shape-morphing ability of cephalopods, can reprogram a wide range of reversible 3D structures (e.g., ear-shaped and asymmetric rocky structures) with geometrical complexity in a single system. c) Schematic illustration showing the operational principle of the 3D magnetic shape-morphing system with diverse shape programming strategies: (i) magnetic encoding (i.e., shape programming), (ii) erasing, and (iii) reprogramming processes. The MMP, consisting of magnetic NdFeB within FM (NdFeB@FM) microparticles embedded in elastomer composite, is a core component for reprogrammable shape reconfiguration. The insets show the phase and movement of NdFeB@FM particles within the MMP in response to the sequential thermal and magnetic stimuli. (Image: Reprinted with permission by Wiley-VCH Verlag. The images in (a) are from the Hanlon Lab website (mbl.edu/research/hanlon-lab), and are reproduced with the permission of R. Hanlon. (click on image to enlarge)
The core of the MMP is a soft elastomer filled with microdroplets of Field’s metal—a low melting point alloy that transitions from solid to liquid at 62 °C—and hard magnetic particles made from neodymium-iron-boron (NdFeB). When the platform is heated above the melting point, the alloy softens, allowing the embedded magnetic particles to respond to external fields and drive shape deformation. Once the desired shape is achieved, cooling re-solidifies the alloy, locking the structure in place. This enables a cycle of softening, reshaping, and hardening that is both fast and reversible.
The magnetization of the material is encoded while in its deformed state using a high-intensity magnetic pulse. This creates a spatially complex and continuous magnetization profile that dictates how the structure will deform when reheated and exposed to a magnetic field.
Importantly, this profile can later be erased and rewritten, enabling the same piece of material to take on entirely new geometries. The ability to magnetically reprogram the shape transformation makes the platform more versatile than existing systems that typically allow only one or two predetermined shapes.
The team demonstrated that the MMP could reliably perform a wide range of deformations including curving, folding, and multi-lobed pop-up structures. Across multiple test conditions, the material consistently showed a shape recovery ratio above 97%, meaning that it nearly perfectly returned to its intended shape.
Shape fixity—the material’s ability to retain a morphed state over time without reversion—remained above 87% even after large deformations. The magnetic response was equally robust. Despite heating and repeated use, the internal magnetization patterns remained stable, enabling consistent actuation under relatively low external magnetic fields.
Response times were rapid. The phase transition from rigid to soft occurred in under 1.5 seconds for thin sheets at 100 °C, and the material re-solidified in around 5–6 seconds at room temperature. Compared to other shape-shifting platforms that may take minutes to reconfigure, this speed enables real-time applications such as interactive displays or responsive robotic components.
One key innovation is the system’s capacity to store and execute multiple magnetic instructions within the same platform. Using magneto-optical microscopy, the researchers visualized distinct magnetization patterns correlating with various morphologies, including letters, dome arrays, and asymmetric surfaces. The encoded magnetic domains directed precise shape transformations under uniform magnetic fields. The use of NdFeB particles as heterogeneous nucleation agents helped eliminate issues like supercooling, improving both the speed and reliability of phase transitions.
To show how these capabilities could be applied, the researchers built several proof-of-concept devices. One was a flower-shaped robot dubbed “FlowerBot,” inspired by the night-blooming evening primrose. This device opens and closes its petals in response to ambient light, using a photodetector and embedded heater to switch between soft and rigid states. When darkness is detected, the heater activates, softening the material so it can bloom in response to a magnetic stimulus. LEDs embedded in the petals activate concurrently, creating a fully integrated sensory and mechanical feedback loop.
Another application focused on tactile displays. The researchers created a refreshable surface that could display visual-tactile information by forming and erasing protrusions in a 5×5 grid. These deformations included letters, icons, and even braille. The display could be reprogrammed by reheating and remagnetizing, offering a dynamic interface that combines both visual and haptic feedback. Importantly, the texture of each display state could also be tuned—soft and pliable while hot, or rigid and load-bearing once cooled.
Security applications were also explored. In one example, secret information was encoded in the magnetization pattern and remained hidden until the appropriate heat and magnetic field conditions were applied. This form of cryptographic display could have uses in secure communication or anti-counterfeiting technologies.
What sets this work apart is its integration of programmability, mechanical robustness, fast actuation, and reusability in a single platform. Unlike systems that require constant energy input to maintain their shape, the MMP holds its configuration passively once cooled, reducing energy consumption. At the same time, its stiffness can be switched on and off as needed, allowing for both durable operation and easy reconfiguration. The seamless coupling of these functions opens up new directions for soft robotics, interactive devices, and tactile information systems.
While the current demonstrations focus on discrete components, the method is scalable. Arrays of actuators can be controlled in parallel or selectively activated for more complex operations. Future work could refine the resolution of magnetization, explore integration with sensor networks, or extend the approach to larger or more intricate surfaces. The ability to reconfigure three-dimensional structures repeatedly and precisely, without permanent deformation, suggests a path forward for building more adaptive and responsive materials that align with real-world functional needs.
Get our Nanotechnology Spotlight updates to your inbox!
Thank you!
You have successfully joined our subscriber list.
Become a Spotlight guest author! Join our large and growing group of guest contributors. Have you just published a scientific paper or have other exciting developments to share with the nanotechnology community? Here is how to publish on nanowerk.com.
