SearcharxivSearch

arXiv · 2303.09326

4D-Printing of Smart, Nacre-Inspired, Organic-Ceramic Composites

Abstract

Additive manufacturing of shape memory polymers has gained tremendous interest in recent years due to their versatile potential applications in various industries, such as biomedicine and aerospace. However, the polymers' mechanical properties, specifically stiffness and strength, often hinder their use in mechanically demanding applications, e.g. as structural materials. In this work we produced nacre-inspired composites with a covalent adaptable network, which enables fast and mechanically lossless self-healing, reshaping, and shape memory capabilities. We demonstrate a novel direct write 4D-printing strategy to print smart, nacre-inspired, organic-ceramic composites based on alumina platelets and vitrimers with up to 3.3 and 26.7 times higher tensile strength and stiffness, respectively, in comparison to the pristine vitrimer. To the best of our knowledge, we introduce for the first time a single step 4D-printing process for nacre-inspired composites, that exploits suspension spreading to align micron sized alumina platelets along a common plane, and which utilizes solvent evaporation to induce polycondensation of the monomers resulting in a vinylogous urethane vitrimer after extrusion of the suspension. This work presents a facile, direct write 4D-printing strategy at ambient printing conditions, establishing a foundation for adaptive additive manufacturing of smart organic-ceramic composites of interest to various industries.

Explore related subjects

Keep this discovery

BibTeXRIS

Benedikt F. Winhard, Philipp Haida, Alexander Plunkett, Julian Katz, Berta Domènech, Volker Abetz, Kaline P. Furlan, Gerold A. Schneider. 2023-03-16. 4D-Printing of Smart, Nacre-Inspired, Organic-Ceramic Composites. https://arxiv.org/abs/2303.09326

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Janus Dipoles: Fundamentals, Realizations, and Emerging Applications

The Janus dipole - featuring orthogonally oriented electric and magnetic dipoles with a 90-degree phase difference - has emerged as a powerful paradigm for wave manipulation. Unlike traditional Huygens dipoles used for directional control, this unique configuration exhibits strongly asymmetric, face-selective near-field behavior while maintaining a quasi-isotropic far-field radiation pattern. These remarkable properties make the Janus dipole an essential platform for directional wave shaping, with wide-ranging applications in on-chip photonics, quantum interactions, and wireless power transfer. This review systematically traces the rapid development of the Janus dipole from its foundational theoretical inception to its diverse implementation platforms across optical, microwave, and acoustic frequencies. In this paper, we explore the governing principles, classify realization strategies into passive Janus dipoles, active Janus dipoles, and advanced near-field coupling control, and highlight emerging frontiers. By bridging foundational electrodynamics with advanced device engineering, this paper serves as an essential reference and roadmap for researchers designing next-generation, highly integrated, and compact wave-manipulation systems.

physics.app-ph

Scattering-robust Imaging of Azimuthal Features with Enhanced Resolution

Imaging through scattering media remains a long-standing challenge in numerous real-world applications, ranging from medical imaging to long-distance sensing. Recently, illumination consisting of a single orbital angular momentum (OAM) mode, which is structured in the azimuthal coordinate, has been shown to provide enhanced resolution for imaging objects with azimuthal features, with the resolution becoming maximum at an optimal OAM value. However, in the presence of scattering, single-mode fields, which are spatially fully coherent, cause the imaging resolution to decrease significantly due to speckle formation. In this work, we employ azimuthally partially coherent fields and experimentally demonstrate imaging of azimuthal features with enhanced resolution in the presence of scattering. We show that lower degree of azimuthal coherence in such illumination leads to increased robustness against scattering while the azimuthal structure of the illumination ensures enhanced resolution. We derive the condition for best imaging resolution, and we report increase of imaging contrast in scattering from about 7% to 50% as the illumination is changed from a single-mode fully coherent field to that of an azimuthal partially coherent field.

physics.app-ph

Influence of magnetic fields on the performance of spin-orbit torque magnetic random-access memory

Spin-orbit torque magnetic random-access memory (SOT-MRAM) offers high speed, ultrahigh endurance, and compatibility with advanced semiconductor processes, making it a promising candidate for next-generation nonvolatile memory. However, intrinsic bias fields in magnetic tunnel junctions (MTJs), originating from reference-layer stray fields and interlayer coupling, cause asymmetric critical switching currents and increased energy consumption. Existing compensation approaches usually introduce additional magnetic layers into the MTJ stack, which increases fabrication complexity and limits wafer-scale integration. Here, we propose a bias-compensation strategy without modifying the MTJ stack by engineering local stray magnetic fields through magnetic filling materials in vertical interconnect access (VIA) channels during the back-end-of-line process. Micromagnetic simulations show that the proposed magnetic filling layer can provide the required auxiliary field for deterministic switching and significantly suppress write-current asymmetry. By optimizing the MTJ position relative to the magnetic filling structure, the write-current bias ratio is reduced from 21.6% in the conventional design to 1.3%. The approach is also applicable to in-plane magnetic anisotropy SOT-MTJs, reducing the bias ratio from 19.8% to -0.2%. Scaling analysis further demonstrates that the compensation effect remains effective when the device size is reduced to 20% of the original dimension (MTJ diameter approximately 10 nm), indicating its potential for high-density SOT-MRAM integration.

physics.app-ph