Source-linked AI summary
Magnetic Dynamic Polymers for Modular Assembling and Reconfigurable Morphing Architectures
Xiao Kuang, Shuai Wu, Yi Jin, Qiji Ze, S. Macrae Montgomery, Liang Yue, H. Jerry Qi, Ruike Zhao
TL;DR
Existing magnetic soft materials need complex geometry and magnetization distributions for sophisticated shape morphing, but structural geometry can remain unchangeable. This work develops a hard-magnetic composite with thermally reversible polymer linkages that supports welding, magnetization reprogramming, and plastic structural reconfiguration. The resulting platform enables programmable modular assemblies and remotely transformed three-dimensional architectures.
Problem
Existing magnetization-reprogrammable materials can retain unchangeable structural geometry, limiting simultaneous structural and material programmability.
Method
The MDP embeds hard-magnetic microparticles in a thermally reversible cross-linked polymer whose bond exchange and cleavage enable welding, dipole reprogramming, and heat-induced elastic-plastic transition.
Results
The MDP enables targeted modular welding, altered morphing modes through magnetization reprogramming, and remotely reshaped three-dimensional architectures from planar structures.
Takeaways & Limitations
The platform provides structural and material programmability and reprogrammability for multifunctional, reconfigurable morphing architectures.
Takeaways & Limitations
Magnetization reprogramming can leave structural geometry unchanged, limiting the resulting material function.
Abstract
from arXiv · showhide
Shape morphing magnetic soft materials, composed of magnetic particles in a soft polymer matrix, can transform shapes reversibly, remotely, and rapidly, finding diverse applications in actuators, soft robotics, and biomedical devices. To achieve on-demand and sophisticated shape morphing, the manufacturing of structures with complex geometry and magnetization distribution is highly desired. Here, we report a magnetic dynamic polymer composite composed of hard-magnetic microparticles in a dynamic polymer network with thermal-responsive reversible linkages, which permit functionalities including targeted welding, magnetization reprogramming, and structural reconfiguration. These functions not only provide highly desirable structural and material programmability and reprogrammability but also enable the manufacturing of structures with complex geometry and magnetization distribution. The targeted welding is exploited for modular assembling of fundamental building modules with specific logics for complex actuation. The magnetization reprogramming enables altering the morphing mode of the manufactured structures. The shape reconfiguration under magnetic actuation is coupled with network plasticity to remotely transform two-dimensional tessellations into complex three-dimensional architectures, providing a new strategy of manufacturing functional soft architected materials such as three-dimensional kirigami. We anticipate that the reported magnetic dynamic polymer provides a new paradigm for the design and manufacturing of future multifunctional assemblies and reconfigurable morphing architectures and devices.
Abstract
The magnetic dynamic polymer combines reversible thermal network chemistry with hard-magnetic particles to enable welding, magnetization reprogramming, and structural reconfiguration. These capabilities support programmable modular assemblies, rapidly reversible morphing, and remotely reshaped three-dimensional architectures.
- Material platform: The MDP embeds NdFeB microparticles in a thermally reversible polymer network that transitions between elastic and plastic behavior through dynamic bond breaking and rearrangement.Bond exchange dominates at mild temperatures, while reversible cleavage occurs at elevated temperature.
- Magnetization reprogramming: Thermal cleavage enables in-situ dipole realignment under a magnetic field, allowing repeated magnetization reprogramming and altered shape-morphing modes.Particles rotate within 5 s and form chain-like structures after 30 s under a 35 mT field.
- Structural reconfiguration: Coupling magnetic actuation with network plasticity remotely reshapes planar kirigami into stress-free, multistable three-dimensional architectures.A planar kirigami transforms into a free-standing helical architecture under a 75 mT out-of-plane field, with bistability accessible magnetically or mechanically.
- Material platform: The MDP retains room-temperature elasticity while its relaxation accelerates with temperature, with the 36.7% modulus time decreasing from 153 min at 50 oC to 46 s at 90 oC.Its apparent zero-shear viscosity also decreases from nearly 10^9 Pa·s at room temperature to 10^6 Pa·s at 90 oC.
Experimental Section
The study prepared dynamic polymer and magnetic dynamic polymer composites, then characterized their mechanical, thermal, relaxation, magnetic, and simulated actuation behavior.
- Material preparation: Furan-grafted prepolymer was synthesized and cross-linked with bismaleimide using varying maleimide/furan ratios.
- Material preparation: 15 vol% NdFeB microparticles averaging 25 µm were incorporated into the polymer mixture to produce magnetic dynamic polymer.
- Processing: Samples were pre-cured at 50 °C, post-treated under vacuum at 60 °C, and hot-compressed at 110 °C to control film thickness.
- Processing: The composites were post-magnetized under 1.5 T impulse magnetic fields before characterization.
- Characterization: Mechanical, thermomechanical, stress-relaxation, calorimetric, and thermal-imaging measurements were performed across specified strain, frequency, temperature, and heating-rate conditions.Tensile, DMA, stress-relaxation, DSC, and infrared imaging methods were used.
Conflict of Interest
The authors declare no conflict of interest.
- The authors declare no conflict of interest.