Gyroid Structure Research Articles

Effect of bicontinuous minimal surface meso-scale geometry on piezoelectric performances of piezoelectric composites

This paper examines the effective piezoelectric properties of ceramic-based composite materials that contain bicontinuous minimal surface structures. Three structures are introduced bicontinuous Schwarz P, bicontinuous Gyroid, and bicontinuous I-WP and the material model is subjected to both compressive and tensile stresses. Using the finite element method, the relationship between the average piezoelectric coefficient and the volume fraction of piezoelectric ceramics is analyzed for different structures. The study reveals that the bicontinuous Gyroid structure exhibits the highest average piezoelectric coefficient of 501 pc/N under a compressive stress of 0.5 Gpa and a piezoelectric ceramic volume fraction of 50%. Additionally, the study compares the three bicontinuous minimal surface structures with 3–3 model piezoelectric composite materials (interconnected random distribution) to explore the piezoelectric ceramic transfer path and the impact of arrangement and combination on piezoelectric properties. The results show that bicontinuous minimal surface piezoelectric composite materials display superior piezoelectric properties, as demonstrated by their high piezoelectric charge coefficient, piezoelectric voltage coefficient, and energy harvesting figure of merit. Overall, this paper provides valuable insights into how the structure of piezoelectric ceramics can be altered to enhance the performance of piezoelectric composite materials.

Mechanical performance of Bio-Inspired Gyroid and Primitive concrete structures under combined compression and torsion Loads: A discrete element method study

Bioinspired lightweight Primitive and Gyroid structures are two well-known TPMS (triply periodic minimal surface) cellular structures. These structures have been shown to possess high specific strength and energy absorption capacity, and thus hold great promise for a range of prefabricated civil engineering applications. As a result, concrete cellular TPMS structures have garnered the attention of researchers. However, prior to this study, no investigation has been carried out on the mechanical properties and failure patterns of concrete Primitive and Gyroid structures under coupled compressive and torsional loads. This lack of knowledge on the behaviour of these structures can lead to safety concerns in construction projects. To better understand the mechanical behaviour of Primitive and Gyroid structures under combined compression and torsion, the discrete element method (DEM) is adopted to simulate the TPMS structures. Both linear contact and nonlinear softbond contact models are utilized to simulate the brittle mechanical behaviour of concrete material. After validating the DEM parameters using published experimental data, the DEM models are subjected to coupled compressive and torsional loads to study their compressive and torsional bearing capacity and cracking patterns. The results indicate that the Primitive based structures outperform the Gyroid based structures in terms of both compressive and torsional resistance. The study is the world's first to reveal that a compressive load enhances the ultimate torsional bearing capacity of TPMS structures, but a torsional load reduces their compressive bearing capacity. Additionally, the loading conditions have little impact on the cracking patterns of the four TPMS structures.

Mechanical performance of carbon fiber‐reinforced polymer cellular structures manufactured via fused filament fabrication

AbstractThis article investigates the mechanical behavior of polyamide and carbon fiber‐reinforced (CFR) polyamide structures produced by Fused Filament Fabrication. CFR improves solid polyamide's tensile strength and modulus by more than 200% and 800%, respectively. The enhancement is highest in the parallel raster due to the alignment of the fibers in the printing direction. The compression tests of gyroid, honeycomb, and Voronoi cellular structures revealed the effect of geometry and fiber reinforcement on energy absorption performance. CFR gyroid infill offers the best performance with a specific energy absorption capacity reaching 10 kJ/kg and an efficiency close to 50%. Fiber reinforcement improves energy absorption by a factor of four or higher while increasing the weight by only 10%. The energy absorption capacity of the reinforced polyamide offers enormous potential for developing new lightweight load‐bearing and impact‐absorbing structures.

Triply periodic minimal surface gyroid structure as effective metal hydride hydrogen storage reactor: Experimental study

Metal hydrides (MHs) are widely recognized as promising materials for hydrogen storage owing to their high volumetric hydrogen density, low temperature and pressure requirements, and exceptional stability. However, the large weight of MHs limits their gravimetric density, thereby posing a significant challenge to their widespread application in the mobility sector. Without compensating for the weight of the reactor, the utilization of MHs in vehicles and mobile applications is expected to remain limited. Additionally, the heat transfer performance of the reactor significantly affects the hydrogen charging and discharging rates. A novel approach is proposed herein to improve the practicality and efficiency of MH-based hydrogen storage systems using triply periodic minimum surface (TPMS) structures as MH reactors and heat exchangers. In this study, a TPMS gyroid structure is fabricated and investigated experimentally. At a relatively low hydrogen charging pressure of 0.5 MPa and room temperature cooling, the proposed reactor with LaNi5 can store hydrogen at 0.6 wt% and reaches full hydrogen capacity within 1020 s. Utilizing the internal heat exchanger of the TPMS gyroid structure increases the absorption and desorption by up to 450% and 240%, respectively.

A Novel Ultra-Wideband Electromagnetic-Wave-Absorbing Metastructure Inspired by Bionic Gyroid Structures.

Traditional honeycomb-like structural electromagnetic (EM)-wave-absorbing materials have been widely used in various equipment as multifunctional materials. However, current EM-wave-absorbing materials are limited by narrow absorption bandwidths and incidence angles because of their anisotropic structural morphology. The work presented here proposes a novel EM-wave-absorbing metastructure with an isotropic morphology inspired by the gyroid microstructures seen in Parides sesostris butterfly wings. A matching redesign methodology between the material and subwavelength scale properties of the gyroid microstructure is proposed, inspired by the interaction mechanism between the microstructure and the material properties on the EM-wave-absorption performance of the prepared metastructure. The bioinspired metastructure is fabricated by additive manufacturing (AM) and subsequent coating through dipping processes, filled with dielectric lossy materials. Based on simulations and experiments, the metastructure designed in this work exhibits an ultrawide absorption bandwidth covering the frequency range of 2-40GHz with a fractional bandwidth of 180% at normal incidence. Moreover, the metastructure has a stable frequency response when the incident angle is 60° under transverse electric (TE) and transverse magnetic (TM) polarization. Finally, the synergistic mechanism between the microstructure and the material is elucidated, which provides a new paradigm for the design of novel ultra-broadband EM-absorbing materials.

Investigation of the mechanical properties triple periodic minimal surfaces lattice structures with functional graded of porosity

In recent years, triple periodic minimal surfaces (TPMS) have attracted attention in many applications such as biomaterials, aerospace, defense industry etc. lightweight components with high strength and functionally graded material (FGM). In particular, the mechanical properties and deformation behavior of these structures under load should be examined. In this study, it was aimed to evaluate the manufacturability and mechanical performance of fixed pore size and functional graded porosity (FGP) lattice structures produced by fused deposition modelling (FDM) method. TPMS primitive and gyroid lattice structures designed in the dimensions of 20 × 20 × 20 mm with fixed 20% pore size and functional graded (FG) from 20% to 40% pore size were used in the experiments. In order to reveal the effects of pore size on mechanical performance, uniaxial compression tests were carried out. In addition, for the validation of the experimental results, compression tests with the finite element method (FEM) were simulated for each sample. In the two different pore size changes tested in the study, the gyroid lattice structure showed the highest mechanical performance compared to the primitive lattice structure. In addition, the FEM results were in good agreement with the experimental results.

Anisotropic structure-property relations of FDM printed short glass fiber reinforced polyamide TPMS structures under quasi-static compression

Triply minimal surface structures of short glass fiber reinforced polyamide with different relative densities were prepared and the effects of induced anisotropy, cell topology, and relative density on the compressive properties were evaluated. Schwarz Diamond, Schoen Gyroid, and Schwarz Primitive structures were 3D printed with relative densities ranging from 0.2 to 0.4, and compression properties along the axial and lateral build directions were determined. Gipson-Ashby numerical parameters required to establish a relation between the cell topology and the compressive properties of the lattice structures were estimated. The plastic deformation and failure mechanisms were analyzed. Results revealed that the compression properties are dominated by the cell topology rather than the relative density. Besides, the present work confirmed that the compressive properties of the lattice structures fabricated with short fiber reinforcement are significantly affected by anisotropy. These structures exhibited a higher compressive modulus and lower peak compressive stress in the lateral direction, which can be attributed to the inline orientation of the short glass fibers. Schwarz Diamond proved to be the stiffest structure, followed by Schoen Gyroid and Schwarz Primitive under axial and lateral compression. Likewise, Schwarz Primitive generated low stresses compared to Schoen Gyroid and Schwarz Diamond. All cell topologies deformed in a controlled manner layer by layer, minimizing undulations in the load-bearing capacity of the structures. D and G structures compressed in the axial direction exhibited significant strain hardening and identical structures compressed in the lateral direction exhibited stable post-yield behavior with negligible undulations which is highly preferred for crashworthiness applications.

A biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties and accelerating osseointegration in spinal fusion.

Spinal fusion is a widely employed treatment of patients with degenerative disc disease, in which a cage is used to replace the disc for spinal fusion. But it often fails for insufficient mechanical strength and poor osseointegration. Here, we designed a polyether-ether-ketone (PEEK)/tantalum (Ta) composite cage with a biomimetic gradient porous micro-structure, simultaneously enhancing mechanical properties and accelerating osseointegration in spinal fusion. In the study, based on the mechanical performances of PEEK and osteogenic potential of Ta, and the three-dimensional (3D) structures of cuttlebone and vertebra, the cages were respectively 3D printed by pure PEEK, PEEK with 5wt% Ta (PEEK/Ta-5), PEEK with 10wt% Ta (PEEK/Ta-10) and PEEK with 15wt% Ta (PEEK/Ta-15), then verified in vitro and in sheep cervical fusion model systematically. Vertebral Gyroid structure PEEK/Ta-15 cage exhibited superior mechanical properties than Cuttlebone-like structure PEEK/Ta-15 cage, closer to the cervical vertebra. Furthermore, PEEK/Ta-15 cage with higher Ta microparticles in PEEK provided a biomimetic gradient porous micro-structure with higher surface energy, guiding cell biological behavior, promoting new bone penetration, and accelerating osseointegration in vivo. In conclusion, the study designed a biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties, accelerating osseointegration and forming an anatomical lock in the fusion segment through composites, mechanical efficiency, surface extension, and pores.

Compressive properties of parametrically optimised mechanical metamaterials based on 3D projections of 4D geometries

The design process of 3D mechanical metamaterials is still an emerging field and in this paper, we propose for the first time, a new design and optimisation approach based on 3D projections of 4D geometries (4-polytopes) and evolutionary algorithms. We find that through iterative parametric optimisation, 4-polytope projected mechanical metamaterials can be optimised to achieve both high specific stiffness and high specific yield strengths. Samples manufactured using a low-stereolithography method were tested in compression. We find that optimised tesseracts (8-cell structures) had a higher specific yield strength (22.8 kN m/kg) than that of honeycomb structures tested out-of-plane (19.4 kN m/kg) and a specific stiffness of (0.68 MN m/kg) which is more than 3-fold that of gyroid structures. The compressive strength to solid-modulus ratio of the 8-cell tesseract is very high (3×10−3), exceeding that of out-of-plane honeycombs, which are themselves closer in value to 5-cell pentatopes (2×10−3). 8-cell and 5-cell structures are in the region of one order of magnitude higher than 16-cell and 24-cell structures (∼2×10−4–8×10−4) and are hence comparable to nanostructured metamaterials. The 8-cell tesseracts are 18% stiffer, 43% stronger, and 19% tougher in compression than out-of-plane honeycomb structures, but unlike honeycombs, 8-cell tesseracts are 3D structures with cubic symmetry. Architecture has a profound effect on the relative consistency of properties with cubically symmetric structures displaying the greatest levels of consistency in terms of both strength and stiffness reduction as a function of pore space. The results presented in this paper showcase the potential of this new class of mechanical metamaterial based on 3D projected 4-polytopes.

Effect of Line Width and Wall Count on the Compressive Strength of Single and Functionally Graded Additively Manufactured ABS Gyroid Structure

Additive Manufacturing (AM) has been in the manufacturing industry for more than a decade. It has aided in producing several intricate objects for several purposes. One of the most used techniques in AM is fused deposition modeling (FDM) wherein a plastic filament is heated to its melting point and deposited layer by layer in a build plate to form a 3D model. Acrylonitrile butadiene styrene (ABS) is one of the commonly used filaments because of its relatively good impact resistance and toughness, and workability in 3D printing various structures. The gyroid structure is a self-supporting structure that has a good strength-to-weight ratio. The compressive strength of single and multiple-layered structures of ABS gyroid lattice structure with different line widths, infill densities, and wall counts was observed. A 0.35 line width with an infill density of 25% and wall count of 3 has a compressive strength of 11.94 MPa, material consumption of 1.87 grams, and printing time of 14 min which makes it the most efficient design for single-layered structures. Among three-layered structures, the combination of infill densities of 25% and 35% is the most efficient with 0.45 line width and 3 walls. It has a compressive strength of 15.87 MPa, printing time of 13 min, and material consumption of 2.3 grams. Nowadays, there are limited research articles on AM of a single structure with gradual varying densities as well as the effect of lesser-known printing parameters on the mechanical properties of AM parts. This study aims to aid future research by providing data on single and functionally graded structures with different line widths and wall counts. With the information from this study, future researchers and designers can further optimize printing parameters to make an efficient design that is light and has sufficient mechanical strength to serve a specific function.

Turbulent Flow and Heat Transfer Enhancement for Turbine Blade Trailing Edge Cooling With Gyroid-Type Triply Periodic Minimal Surfaces

Abstract The Gyroid is a type of triply periodic minimal surface (TPMS) that has interconnected, perfectly curved topologies and excellent thermomechanical properties. Due to its topological feature to enhance heat transfer and self-support structure, this study presents numerical investigations of the flow, heat transfer, and pressure loss in various Gyroid architectures in a wedge-shaped channel, representing a trailing edge cooling for gas turbine blades. The Gyroid structures are partly arranged near the outlet of the wedged channel or are fully filled within the wedged channel. The local and overall flow and heat transfer mechanisms with different Gyroid configurations are compared to the baseline pin fins within the Reynolds number range of 10,000–30,000. The results show that for the case with partly infilled Gyroid structures, the overall heat transfer enhancement is higher by 39–102%, and the related pressure loss is higher by 93–154% than the baseline pin fins. For the case with fully infilled Gyroid structures, the total heat transfer is superiorly higher by 157–188%, and the related pressure loss is higher by 248–555% than the baseline pin fins. For all the Gyroid configurations, obviously improved cooling uniformity is achieved on the whole trailing edge wall. The significant heat transfer enhancement in the trailing edge channel with Gyroid structures is mainly due to a much increased wetted area, the generated helical and impingement flow through the curved interconnected channels and improved flow distribution within the wedged channel.

Study of cellular femoral stem for stress shielding and interface stability

Implant failure is due to stress shielding and interface micromotion. The application of porous structures in the femoral implant has a great effect on reducing stress shielding and improving the stability of the bone-implant interface. The performance of femoral stems with triply periodic minimal surface (TPMS) structures, IWP, and Gyroid structures was evaluated using finite element analysis. We studied the stress shielding phenomenon of the porous femoral stem based on the ability of stress transfer to the femur. The micromotion at the bone-implant interface was explored for different porous femoral stems. The effect of gradient structure design was investigated in the axial direction of the stem. These gradient designs involved a stem with an increasing volume fraction in the axial direction (IAGS) and a decreasing volume fraction along the stem (DAGS). The results showed that the axial stiffness of the stem has a direct effect on stress shielding and an inverse relation to bone-implant micromotion. The finite element analysis results inferred that bone resorption is higher in the stems with IWP structure than in Gyroid at the same volume fraction. Axially graded stems transfer higher stress to the femur than homogenous porous stems. DAGS design of IWP and Gyroid and IAGS Gyroid increased the stress on the proximal-medial of the femur. Homogeneous porous stems with high porosity (80% porosity for IWP and 70% porosity for Gyroid) and DAGS design exhibited low stress shielding and controlled bone-implant interface micromotion within an acceptable range for bone ingrowth.

Programmed Self-Assembly of Single Colloidal Gyroids for Chiral Photonic Crystals.

Gyroid structures are of extensive interest because they provide a rich platform for chiroptics as well as topological photonics. While the double-gyroid morphology as a bicontinuous structure is not uncommon in self-assembled soft materials, direct self-assembly of single-network gyroids has proven elusive. Here, an enantiomorphic pair of single-gyroid crystals comprising colloidal spheres is presented, and two distinct routes are demonstrated for programmed self-assembly of each single colloidal gyroid enantiomorph from rationally designed patchy spheres. The designer colloidal patchy spheres, which closely hew to their synthetic feasibility, are chiral, having either two staggered rectangular patches at opposite poles or four circular patches arranged in a well-defined geometry. The single colloidal gyroid, as well as its inverse structure, is shown to support a wide complete photonic bandgap in addition to exhibiting rich chiroptical properties, making them attractive chiral photonic crystals. The versatility of this single colloidal gyroid, the bottom-up routes devised here in silico, and the robustness of the design space for the chiral colloidal patchy spheres together make a strong case for single colloidal gyroids to supersede colloidal diamond, as a target for programmed self-assembly, in the quest for a photonic crystals operating at opticalfrequencies.

Evaluating the in Vitro Mechanical Responses of Stem Cell Under Fluid Perfusion in Different Porous Scaffolds

Abstract A suitable scaffold architecture is always desirable to get a favorable tissue response for bone tissue engineering. In this regard, a fluid-structure interaction analysis was carried out on different porous scaffolds to observe the in vitro mechanical responses due to fluid flow, followed by a submodeling method to obtain the cellular deformation and strain. Different types of scaffolds were designed based on different porosity and architecture. The cell was modelled with cytoplasm, nucleus, cell membrane, and cytoskeletons. The main objective of the study is to examine the variation of cellular responses due to different porosity and architecture of the scaffold. The results of this study highlight that permeability is higher in the case of gyroid structure and wall shear stress (WSS) is higher in the case of diamond structure. The permeability of all scaffolds increases with the increase of porosity. The opposite trend is shown in the case of WSS within scaffolds. The cell is showing higher deformation when it is placed on the front position of the scaffold towards the direction of fluid flow. This study will guide us in predicting an ideal scaffold for better cell growth.

Analysis of gyroid heat exchangers for superconducting electric motors

In this study, gyroid structured heat exchangers are critically analysed in a counterflow arrangement. These are to be analysed to measure their performance in the case of superconducting electric motors using cryogenic fluids at low temperatures. Gyroid structures are useful in heat exchanger design, as they offer more varied and complex geometries that can optimise heat transfer to be more efficient, compared to traditional heat exchanger designs. The manufacture of these heat exchangers is made possible using additive manufacturing, as the complex shape of these structures cannot be made through traditional methods. Simulation analysis results of the gyroid structures are compared to a basic tubular counterflow heat exchanger arrangement, which can be made from more traditional methods. Physical printing of the model is also demonstrated to show its practicality. The comparison of results elucidated the overall effectiveness of the gyroid structures, and how geometries can optimise overall energy transfer, considering heat transfer from fluids, and pressure loss from fluid flow.

Research on Sound Absorption Properties of Tri-Periodic Minimal Surface Sandwich Structure of Selective Laser Melting Titanium Alloy

Triply Periodic Minimal Surface (TPMS) sandwich structure has the characteristics of lightweight, high specific strength, specific stiffness, vibration, and noise reduction. There is relatively little research on its sound absorption performance. TPMS sandwich structure based on selective laser melting (SLM) technology can achieve precise control of structure type, porosity, and so on, and has broad prospects in noise control applications. In this paper, the sandwich structure is designed based on tri-periodic minimal surface implicit function, and the titanium alloy sandwich structure is formed by SLM technology, and the sound absorption performance of titanium alloy TPMS sandwich structure is studied. The effects of volume fraction, panel thickness, and cell layer number on the sound absorption performance of the two TPMS structures were systematically analyzed using the transfer function method. The results show that: The GP10 sandwich structure with the volume fraction of 20%, the thickness of the panel is 1.0 mm, and the number of cell layers is 3C parameter combination has better sound absorption performance and higher sound absorption bandwidth, and the sound absorption coefficient is 0.36. For Ti6Al4V sandwich sound absorption structure, it is not suitable to design too thick panels. When the volume fraction is lesser, the increase of the tortuosity factor τ improves the sound absorption performance of the two structures, and excessive volume fraction leads to a decrease of sound absorption performance. The increase of cell layers can broaden the sound absorption bandwidth of the two structures, and the sound absorption capacity increases and then decreases in the range of 150–6400 Hz. The Gyroid structure mostly exhibits resonance sound absorption mechanism, while the Diamond structure exhibits resonance sound absorption mechanism combined with the viscous loss of sound wave. The work done in this paper can provide a theoretical basis for the study of the sound absorption characteristics of TPMS sandwich structure.

Achieving structural white inspired by quasiordered microstructures in Morpho theseus

As one of the most fascinating phenomena, structural whiteness in natural organisms serves important functions in thermoregulation and mating. However, the architectures that cause visible broadband reflection are often in quasiordered distributions, which hinders systematic research on their color formation mechanisms. Here, through numerical analysis, the architectures in Morpho theseus scales are shown to be distributed in various tubular morphologies between tubular and gyroid structures. Then, the mechanism of structural white is discussed using the numerical model built with the combination of a periodic numerical framework and random elements. Thermodynamic experiments indicate that the white scales can efficiently help reduce the temperature of butterfly wings under a direct light beam. Our work provides a concise method for analyzing quasiordered structures. The methodology developed by this numerical model can facilitate a deep understanding of the performance improvement facilitated by these structural characteristics. Corresponding solutions can guide the design of nano-optical materials to achieve an efficient cooling, camouflage, and photothermal conversion system.

Experimental and Numerical Modal Characterization for Additively Manufactured Triply Periodic Minimal Surface Lattice Structures: Comparison between Free‐Size and Homogenization‐Based Optimization Methods

Homogenization‐based topology optimization (HMTO) is one of the most extensively used grading methods to generate functionally graded lattice structures (FGLs). However, it requires a precharacterization of the lattices, which is time‐consuming. As a remedy, free‐size optimization‐based graded lattice generation (FOGLG) is explored as an alternative method to generate the FGLs. This article builds on the authors’ previous work in which the HMTO and FOGLG approaches are studied to improve the dynamic characteristic of a design by using a single lattice type, namely, double gyroid (DG) structure. To show applicability of the proposed methods, different lattice types including diamond (D), gyroid (G), and I‐WP are employed to create FGLs herein. The frequency response analysis is performed, and the results from HMTO and FOGLG are compared in terms of their accuracy and efficiency. The optimized designs are then reconstructed by relative density mapping (RDM) and enhanced relative density mapping (ERDM) methods. The fabricated test samples made of cobalt–chromium using the direct metal laser melting (DMLM) technique are then experimentally validated using a laser vibrometer. The results reveal that HMTO and FOGLG can be used on the lattice types with a variety of configurations and relative densities.

Numerical simulations of gyroid structures under compressive loads

Numerical simulations are essential for predicting the mechanical properties of different structures like gyroids that center this study. Three different methods are explored: shell elements, solid elements, and homogenization. Results reveal that homogenization is only suitable for obtaining the properties in the elastic zone, whereas solid models can determine also the behaviors in the plateau zone and the densification point. In the case of shell elements model, it can predict the elastic behavior model and the levels of stress in the plateau zone but with a lower accuracy than the solid element, but it cannot predict the densification point.

Additively Manufactured Mechanical Metamaterial‐Based Pressure Sensor with Tunable Sensing Properties for Stance and Motion Analysis

Mechanical metamaterials are attracting considerable attention due to their unique properties not found in natural materials. Advanced geometrical shapes such as Menger cubes, origami templates, and gyroids offer exciting avenues for device engineering. In addition, the recent developments of various additive manufacturing technologies have expanded materials selection and geometrical complexities. Herein, a piezoresistive pressure sensor based on a 3D‐printed gyroid structure with a conformal coating of carbon nanotubes (CNTs) is presented. The gyroid structures are printed using fused deposition modeling (FDM) 3D printing with thermoplastic polyurethane (TPU), providing mechanical robustness even at low densities. By altering the relative density of the gyroid structure, Young's modulus can be tailored, ranging from 0.32 MPa at 30% relative density and 3.61 MPa at 80% relative density. The presented gyroid‐based pressure sensor achieves a wide sensing range of up to 1.45 MPa and a high sensitivity of 2.68 MPa−1. The sensor is integrated into a shoe for wearable applications, demonstrating its mechanical robustness and potential for human stance and motion monitoring.