Macrostructural Design Research Articles

Multiphase ceramic SiBCN-ZrO2/ZrC/ZrB2/SiC with ultra-wide bandwidth electromagnetic absorption

Broadband electromagnetic (EM) absorption is challenging for non-magnetic monolithic materials without any macro-structural design, primarily due to the impedance mismatch and insufficient EM dissipation. This study reports a multiphase ceramic made of SiBCN-ZrO2/ZrC/ZrB2/SiC, with an ultra-wide bandwidth EM absorption capability. The composites were prepared using a polymer-derived ceramic (PDC) method. The multiphase EM absorbers (ZrO2/ZrC/ZrB2/SiC) synergistically tune the dielectric properties and impedance matching of the composite ceramics, allowing the cross-band EM absorption at a low thickness. The SiBCN-ZrO2/ZrC/ZrB2/SiC composite ceramics pyrolyzed at 1400 °C for 2 h has an effective absorption bandwidth (EAB) of 11.06 GHz at a thickness of only 2.4 mm, covering parts of the C-band, the entire X-band and Ku-band (6.94–18.00 GHz). This research proposes a strategy for producing a monolithic composite ceramic with broadband EM absorption, which can also be used in high-temperature harsh environments.

Hierarchical porous structure design and water activation in hydrogels containing hyperbranched peach gum polysaccharide for efficient solar water evaporation

Solar-powered interfacial evaporation is a developing and sustainable technique increasingly utilized in desalination and wastewater purification. This technology involves the creation of cellulose nanofiber (CNF)/polylactic acid (PLA) composite aerogels through the Pickering emulsion approach. Self-floating aero-hydrogel (E-VGP) with a hierarchical porous structure was formed on a viscous mixture containing polyvinyl alcohol (PVA), peach gum polysaccharide (PGP), and polypyrrole (PPy) via an in-situ polymerization process. Furthermore, by modifying the hydrolysis time of PGP with a hyperbranched polyhydroxy structure, VGP hybrid hydrogels of varying microscopic molecular sizes were produced. Additionally, solar vapor generators (SVG) with diverse macroscopic structures were fabricated using molds. The V8G4-12hP0.2 hybrid hydrogel, synthesized using PGP hydrolyzed for 12 h, exhibited an evaporation enthalpy of water at 1204 J g−1. This capacity effectively activates water and enables low enthalpy evaporation. Conversely, the macrostructural design allows the cylindrical rod raised sundial-shaped structure of SVG3 to possess an expanded evaporation area, minimize energy loss, and even harness additional energy from its nonradiative side. Consequently, this micro-macrostructural design enables SVG3 to attain an exceptionally high evaporation rate of 3.13 kg m−2 h−1 under 1 Sun exposure. Moreover, SVG3 demonstrates robust water purification abilities, suggesting significant potential for application in both desalination and industrial wastewater treatment.

Experimental study of dual nano-network, high-temperature resistant aerogel material as an integration of thermal management functions

Thermal management system is highly desirable to guarantee the performance and thermal safety of lithium-ion batteries, but it reduces the energy density of battery modules and even is unable to provide highly effective protection. Here, a thermal management function integrated material is presented based on high-temperature resistant aerogel and phase change material and is applied at both charge–discharge process and thermal runaway condition. In this sandwich structure Paraffin@SiC nanowire/Aerogel sheet (denoted as PA@SAS) system, SiC nanowires endow the middle aerogel sheet (SAS) a dual nano-network structure. The enhanced mechanical properties of SAS were studied by compressive tests and dynamic mechanical analysis. Besides, the thermal conductivity of SAS at 600 °C is only 0.042 W/(m K). The surface phase change material layers facilitate temperature uniformity of batteries (surface temperature difference less than 1.82 °C) through latent heat. Moreover, a large-format battery module with four 58 Ah LiNi0.5Co0.2Mn0.3O2 LIBs was assembled. PA@SAS successfully prevents thermal runaway propagation, yielding a temperature gap of 602 °C through the 2 mm-thick cross section. PA@SAS also exhibits excellent performance in other safety issues such as temperature rise rate, flame heat flux, etc. The lightweight property and effective insulation performance achieves significant safety enhancement with mass and volume energy density reduction of only 0.79% and 5.4%, respectively. The originality of the present research stems from the micro and macro structure design of the proposed thermal management material and the combination of intrinsic advantages of every component. This work provides a reliable design of achieving the integration of thermal management functions into an aerogel composite and improves the thermal safety of lithium-ion batteries.

Carbon nanofiber aerogel microspheres with heterogeneous skin-core structure for broadband electromagnetic wave absorption

The advancement in the miniaturization of carbon aerogels into micro-sized spheres represents a significant development in the creation of ultralight, broadband microwave absorbers. Notwithstanding this innovation, there is still a considerable challenge in optimizing microwave absorption (MA) performance through heterointerface engineering within aerogel microspheres. Herein, we have developed skin-core heterogeneous aerogel microspheres by the in situ generation of ZIF-67 nanocrystals on the wet-spun aramid nanofiber (ANF) aerogel microspheres, followed by a high-temperature carbonization process. The resulting Co@C nanoparticle-enshrouded ANF-derived carbon nanofiber aerogel microspheres (Co@C/CNFAMs) demonstrate an exceptional equilibrium between impedance matching and multi-faceted attenuation. Remarkably, the Co@C/CNFAM2 sample attains a maximum effective absorption bandwidth of 8.72 GHz, while maintaining an ultralow filler proportion of 1.5 wt%. Moreover, the Co@C/CNFAM3 sample achieves a minimum reflection loss of −72.34 dB with a filling ratio of 1.2 wt%. Our findings offer a refined approach to the intricate engineering of heterostructures, along with the strategic macrostructural design, paving the way for the development of aerogel-based microwave absorbers that represent the next step in material science innovation.

3D Printed MXene-Based Wire Strain Sensors with Enhanced Sensitivity and Anisotropy.

Stretchable strain sensors play a crucial role in intelligent wearable systems, serving as the interface between humans and environment by translating mechanical strains into electrical signals. Traditional fiber strain sensors with intrinsic uniform axial strain distribution face challenges in achieving high sensitivity and anisotropy. Moreover, existing micro/nano-structure designs often compromise stretchability and durability. To address these challenges, a novel approach of using 3D printing to fabricate MXene-based flexible sensors with tunable micro and macrostructures. Poly(tetrafluoroethylene) (PTFE) as a pore-inducing agent is added into 3D printable inksto achieve controllable microstructural modifications. In addition to microstructure tuning, 3D printing is employedfor macrostructural design modifications, guided by finite element modeling (FEM) simulations. As a result, the 3D printed sensors exhibit heightened sensitivity and anisotropy, making them suitable for tracking static and dynamic displacement changes. The proposed approach presents an efficient and economically viable solution for standardized large-scale production of advanced wire strain sensors.

Macrostructural Design Approach of the Monolithic Catalyst and Its Application in Nitrobenzene Hydrogenation

Macrostructural Design Approach of the Monolithic Catalyst and Its Application in Nitrobenzene Hydrogenation

Enhancing the crack initiation resistance of hydrogels through crosswise cutting

The achievement of tough adhesion between hydrogels and solid surfaces has significantly expanded the potential applications of hydrogels. This robust adhesion is commonly attained by combining tough hydrogels with strong interfacial bonding and it is reflected in high adhesion toughness. However, the practical use of such strategies is limited since enhanced adhesion diminishes rapidly after cyclic loading. Furthermore, relying solely on adhesion toughness as a measure of adhesion quality may underestimate the adhesive's bearing capacity. To address these issues, here we introduce a macro-structural design strategy called crosswise cutting in hydrogels and propose a new measure of hydrogel adhesion named crack initiation resistance. This strategy can significantly enhance hydrogel adhesion by increasing the peak peel force while constraining the crack initiation length, thus improving the crack initiation resistance. The toughening mechanism behind this strategy is further explored by decomposing the crosswise cutting into longitudinal and transverse cuttings. Through extensive experiments, we demonstrate that longitudinal cutting can increase both the peak peel force and crack initiation length during peeling. Conversely, transverse cutting can constrain the crack initiation length while maintaining a high peak peel force. To quantitatively evaluate the crack initiation resistance of an adhesion system, we define a new parameter, the critical crack initiation energy release rate (Gc*), which considers both the peak peel force and crack initiation length. Theoretical derivations of Gc* for hydrogels with longitudinal and transverse cuttings are provided. By varying cutting types, hydrogel thickness, and cut sizes, the value of Gc* can be significantly increased, with the optimal choice being the crosswise cutting satisfying specific dimensions. The underlying mechanisms pertaining to the increase of Gc* via crosswise cutting are explained by the stress de-concentration effect, and the value of Gc* can be predicted by the macroscopic Lake-Thomas model. It is hoped that this study will draw attention to the assessment of the adhesion quality of hydrogels in practical applications and provide some new insights for the design of future soft adhesives.

Optimizing additively manufactured macro-fin structure designs for enhanced pool boiling of dielectric fluids

This paper presents the results of the saturated pool boiling heat transfer performances of macrostructured fins fabricated by Selective Laser Melting, a metal additive manufacturing technique. A plain surface, two-dimensional triangular and rectangular fins, and three-dimensional pin and segregated fin array designs investigated in this study were fabricated using AlSi10Mg. A dielectric fluid, HFE-7100, was used as the cooling medium in a water-cooled thermosyphon to test the structures under atmospheric conditions. A macro-fin design optimization approach was developed by experimentally characterizing the boiling performances and bubble dynamics in fin arrays with different fin parameters such as fin topology, angle, and height. From the results obtained, this study optimized and tuned the macrostructure design to eliminate the detrimental bubble dynamics that were identified through high-speed visualization. Following a systematic study of the boiling characteristics of two-dimensional triangular and rectangular fins, and three-dimensional pin fins, the segregated fin array was developed to tackle the unfavorable bubble dynamics in these conventional fin geometries to enhance both critical heat flux and heat transfer coefficient. Various performance metrics were used to compare and evaluate the boiling performances of different fin topologies. From our studies, the segregated fin specimen (Seg-3) was determined to achieve the best balance between critical heat flux and heat transfer coefficient enhancements, attaining a critical heat flux of 64.19 W/cm2 and a maximum heat transfer coefficient of 2.22 W/cm2·K, enhancing critical heat flux and heat transfer coefficient by up to 97.2 % and 43.1 % as compared to the plain surface, respectively. Furthermore, Seg-3 has achieved boiling enhancements with only 334 mm2 and 50.6 mm3 of surface area and fin volume, respectively, a substantial surface area and fin volume reduction as compared to conventional macro-fin geometries with the same fin height. In all, this work not only provides fundamental insights into the bubble dynamics in various macro-fin structures and their influence on the boiling performance, but it also presents a macro-fin design optimization strategy that can be adopted for other immersion cooling applications.

Graphite films/copper composites with high thermal conductivity in the vertical direction obtained by radial structural design

To obtain highly thermally conductive materials in both the X-Y and Z directions, a reinforcement phase macrostructure design was used to improve the thermal conductivity (TC) of the composites. We fabricated copper matrix composites with a radial graphite film skeleton via fast hot pressing technology. The results showed that the radial structure design was an effective strategy. The TC in the Z-direction of composites with radial structures is 10 times higher than that of laminated composites while maintaining a high TC in the X-Y direction. The TC of the composites was 778 W/mK in the X-Y direction and 287 W/mK in the Z direction when the graphite films were at a 20 % volume fraction. Composites have the potential to become thermal management materials.

Material thermal extrusion of conductive 3D electrodes using highly loaded graphene and graphite colloidal feedstock

Evolution in the energy storage field requires the development of more sustainable and efficient high-performance electrochemical storage devices (EESDs). Additive manufacturing (AM) opens unique opportunities to improve the efficiency and the electrochemical response by the design of 3D electrodes and the increasing of exposed active surface area impossible to achieve by other processing techniques. In other to reach high-performance EESDs, carbonaceous species are well-established as electroactive materials owing to their electronic properties, low cost, and sustainable origin. Although the materials have been widely investigated, there is a lack of feedstock development for the fabrication of EESDs by AM technologies. This work presents the fabrication of metals free light conductive filaments for material thermal extrusion (MTE) by formulating PLA-based composites with a high content of colloidal graphite and graphene (15–25 vol%). By the colloidal characterization and surface modification of the carbonaceous species, an improved distribution and enhanced platelet/polymer bond were achieved, provoking the inorganic phase's orientation during the extrusion process. Prepared filaments were characterized to analyze the influence of the microstructural anisotropy on thermal, thermorheological, mechanical, and electrical properties. Subsequently, developed filaments were used to print complex electrodes by MTE, enhancing the electrochemical properties of the electrodes with superior control of the macrostructural design. The developed colloidal filaments with an oriented inorganic microstructure, not only allow a defined shaping of the outer structure of the electrodes but also let the design of completely different microstructures. Consequently, different microstructural configurations were printed increasing the number of conduction paths in the polymeric matrix to achieve high electric conductivities (22 S.m-1) in printed electrodes.

Micro-, Meso- and Macrostructural Design of Bulk Metallic and Polymetallic Materials by Wire-Feed Electron-Beam Additive Manufacturing

Abstract Additive manufacturing of metal materials is one of the most promising technologies in modern industry. A wide variety of current additive manufacturing techniques allow rapid prototyping and industrial production of different-sized products from various structural and functional materials. The structure and physical-mechanical properties of the metal products fabricated by electron-beam additive manufacturing (EBAM) within nonstationary metallurgy in a local molten pool often differ from those of the products fabricated by conventional metallurgy due to different crystallization mechanisms, sequence and completeness of phase transformations, and heterogeneous/homogeneous chemical composition of the resulting material. The possibility to control local metallurgical processes in the molten pool is the key advantage of the EBAM technology. It allows one to control the structure, composition, and properties of mono- and polymetallic, graded, composite and heat-resistant materials in order to obtain products with the desired chemical composition, macroscopic architecture, and microscopic structural parameters. As any new industrial technology, the EBAM method requires the development of scientifically based approaches to the choice of materials and production conditions. Here we provide an overview of the scientific approaches developed for electron-beam additive manufacturing of products from metals and alloys using wire or rods as a feedstock. The range of the studied materials includes additive materials based on copper, bronze, aluminum, nickel, titanium alloys, and different steels, as well as aluminum-based functionally graded materials and copper-based graded materials. The most important research findings are summarized.

A Concurrent Topology Optimization Model for Dynamic Property of Structures with Connectable Graded Microstructures

Lattice structures composed of porous microstructures have attracted considerable attention due to their useful light-weight and multiphysical properties. Their mechanical properties are often a major concern in the design problem. However, unlike in the case of static stiffness maximization, few theoretical results can be used to guide the dynamic property design of such structures and their microstructures. In this paper, we present a numerical method of concurrent topology optimization for maximizing the natural frequencies of structures consisting of layer-wise graded microstructures. Both the configurations of graded microstructures and their spatial distribution in the macrostructural design domain are simultaneously optimized under constraints imposed on the macro- and microscales. The applied microscale design constraint still retains desired design space by allowing designable volume fractions of different microstructures under the total material usage restriction. The designable connective region technique is employed to guarantee the connectivity between different layers of microstructures. Numerical examples demonstrate the effectiveness of the proposed method. Compared to the uniform-lattice structural design, the proposed method is able to yield improved dynamic performance.

Investigation of concurrent multiscale topology optimization for designing lightweight macrostructure with high thermal conductivity

Lightweight and high heat conductive solid structures are playing important role in various fields of engineering. To maximize the design performance for such structures, we investigated multiscale topology optimization for excessive lightweight heat-conductive porous structures and introduced a mathematical optimization model formulation for concurrently optimizing the structures (macrostructure) and the constitutive pores (microstructure). The microscale is considered a representative volume element and designed using the asymptotic homogenization method. For each iteration, the effective heat conductivity tensor of the microstructure is evaluated during the optimization process and used as the heat conductivity of the macrostructure. Sensitivity analysis on this concurrent optimization scheme was derived to address the macro and microstructure coupling. To broaden the scope of the research applicability, three topology optimization methods, i.e., SIMP, level set and ESO are investigated, and the results are compared and discussed. The suggested formulations showed a successful application of the concurrent multiscale optimization formulations and good coupling on the macro and microscale. Also, the formulations demonstrated a strong influence between the macro and the microscale of the design problem for the topology optimization methods. Increasing the design freedom by introducing various microstructures for the macro design domain showed superior performance associated with attaining high weight reduction. In addition, the concurrent optimization scheme has enabled the microstructures to attain a good spatial layout of materials while taking into account the weight reduction constraint. The spatial arrangements of the designed microstructures have achieved conducting heat in a shorter path toward the heatsink zone of macrostructure design. This allows attaining good performance with high weight reduction. Furthermore, numerical examples of different mesh numbers were used to study mesh dependency of multiscale topology optimization. The scope of the study was broadened by the inclusion of 3D case studies. Implementing Isosurface technique to achieve high detail model was also used to attain high detailed concurrently optimized design with minimal mesh number to minimize the computational cost. The 3D optimized case was investigated experimentally.

Interactive Effects of Five Dental Implant Design Parameters on the Peak Strains at the Interfacial Bone: A Finite Element Study.

The aim of this study was to evaluate and compare the effect of changing five macrostructural design parameters of dental implants on the peak strains experienced by the interfacial bone. Five geometric variables, including three body-related (implant length, diameter, and taper) and two thread-related (thread depth and thread angle) parameters, were defined. The alveolar bone was modeled as a block with anisotropic and linearly elastic properties with 20-mm height and 12-mm buccolingual and mesiodistal dimensions. Oblique occlusal loads (100-N vertical and 20-N horizontal) were applied to the abutment surface. A total of 162 models with different designs were defined by implementation of a full-factorial design. The peak values of the compressive and tensile principal strains in the cortical and cancellous bones were calculated by finite element analysis (FEA). Implant diameter and length had maximum and minimum effects on the peak compressive and tensile strains at the cortical interface, respectively. Implant diameter and thread depth had maximum and minimum effects on the maximum compressive strain at the cancellous interface, while thread angle and length had maximum and minimum significant effects on the maximum tensile strain at the cancellous interface. The interaction of thread parameters and taper has the greatest effect on the peak compressive and tensile strains at the cancellous interface and also on the peak tensile strain at the cortical interface, while body-related parameters are more effective on the peak compressive strain at the cortical interface.

Scientific approaches to micro-, mesoand macrostructural design of bulk metallic and polymetallic materials by wire-feed electron-beam additive manufacturing

Scientific approaches to micro-, mesoand macrostructural design of bulk metallic and polymetallic materials by wire-feed electron-beam additive manufacturing

Macrostructural design of highly porous SiOC ceramic foams by preceramic polymer viscosity tailoring

Highly porous SiOC ceramic foams with gradient or uniform macrostructures were obtained through polymer derived ceramic routes. Precuring of preceramic polymers and introduction of SiO 2 powders were used to tailor precursor viscosity and hence SiOC foam macrostructure. Effects of polymer viscosity on porosity, pore size, pore distribution were investigated by light microscopy and micro-computed tomography techniques. SiOC ceramic foams. Foams from one unmodified precursor, showed pore size gradient with small pores located at bottom and large pores at the top. To address this non-uniformity, the viscosity of the precursor was increased by pre-curing the preceramic polymer, which resulted in decrease of the average pore size and improvement in pore size uniformity. For a different system with a self-foaming preceramic polymer, because of the simultaneous release of foaming gases and rapid increase in viscosity during crosslinking, the foam had non-uniform macrostructure with large pores and thick struts at the bottom. By addition of SiO 2 fillers, the crosslinking reaction rate was reduced leading to homogeneous pore nucleation and uniform small pore size foams.

Functionally Graded Non-Periodic Cellular Structure Design and Optimization

Abstract Topological tailoring of materials at a micro-scale can achieve a diverse range of exotic physical and mechanical properties that are not usually found in nature. Modification of material properties through customizing the structural pattern paves an avenue for novel functional products design. This paper explores a non-periodic microstructure design framework for functional parts design with high-strength and lightweight. To address the geometric frustration problem commonly found in non-periodic microstructure designing, we employ a smooth transition layer to connect distinct structural patterns and thus achieve functional gradation among adjacent microstructures. The concept of spatial control points is introduced for the interpolation of this transition layer. To achieve a high-strength macro-structural performance for designing functional parts, we formulate the control points as the design variables and encapsulate them into a macro-structural design optimization problem. Given that our objective function involves expensive finite element (FE) simulations, a Bayesian optimization scheme is exploited to address the computational challenge brought by the FE simulation. Experimental results demonstrate that the proposed design framework can yield both functionally graded lightweight structures and high-strength macro-mechanical performance for the designing parts. The compatibility issue of non-periodic microstructure design is well-addressed. Comparative studies reveal that the proposed framework is robust and can achieve superior mechanical performance to design functional parts with spatially varying properties.

Topology optimization of arbitrary-shape multi-phase structure with structured meshes based on a virtual phase method

In the community of topology optimization, the contradiction between the frontier research with structured meshes and the complex geometry in the real-world problems has existed for a long time. Structured mesh is attractive in convenient application of loads and boundary conditions, and easy implementation of GPU parallel calculation. Therefore, unlike existing researches solving the issue through unstructured elements, this paper presents an easy-to-accomplish virtual phase method (VPM) based on structured meshes, to systematically solve the problems with complex geometries and arbitrary non-design domains. Structural geometry is denoted by the extended regular design domain and void region initially placed at the border of the extended domain. Based on the extended idea of composite material interpolation in multi-phase density-based topology optimization approaches, the extended structural design domains and the pre-defined non-design domains are considered as the optimized phases in the structure, and they are defined by discrete variable fields. Subsequently, the structural optimization is implemented like as the traditional multi-material topology optimization process. Numerical examples accounting for minimum compliance are presented to demonstrate the effectiveness of the proposed method, including multi-phase macrostructural design, the ease with which the method can accommodate passive regions, and how the length scale constraints are used to devise graded porous infill morphology within a given shell. At last, the manufacturability of the optimized designs is discussed to further verify the applicability of the proposed method. Our approach provides those front researches based on structured meshes with an easily accessible access, to be straightforwardly applied for any complex-domain design problem.

P, N-codoped carbon nanofibers confined ultra-small bimetallic NiCoP for highly efficient overall water splitting

Integrating the unique metalloid behaviour of monometallic phosphides and modified local electronic/geometric structures of active sites, bimetallic phosphides have emerged as promising candidates for water splitting reaction, but they are still synthesized by toxic, corrosive, and high-temperature methods, which inevitably resulted in an increase of particle size and the decrease of catalytic activity area. Herein, the ultra-fine bimetallic NiCoP catalysts in-situ embedded in P, N-codoped carbon nanofibers (NiCoP@PNCNF) were successfully fabricated via a facile electrospinning method with the help of phytic acid. Profiting from the unique macro-structural design and micro-electronic/geometric modification, as-prepared NiCoP@PNCNF catalysts exhibited excellent catalytic performance both for HER (η10 = 98 mV) and OER (η10 = 260 mV) in terms of the low overpotential and robust stabilities in alkaline solution. Meanwhile, XAFS analysis further demonstrated that the remarkable catalytic performance not only attributed to the introduction of heteroatom-doped carbon fibers as their improvements in the corrosion resistance, anti-agglomeration abilities, and conductivity, but also benefited from the local electronic/geometric structure alternations as the strong synergic effects between Ni/Co and P atoms. For practical application, the water splitting performance based on NiCoP@PNCNF electrodes was also investigated and exhibited a lower splitting potential (EJ=10, 1.645 V) over long-term stability tests. These insightful findings undoubtedly shed light on the design and fabrication of cost-effective and robust bifunctional transition-metal phosphides electrocatalysts.

High-Performance Solar Steam Generator Based on Polypyrrole-Coated Fabric via 3D Macro- and Microstructure Design.

Due to the abundance and easy availability of solar energy resources, solar-driven water evaporation provides a sustainable way to obtain clean water from wastewater and seawater. However, achieving a high evaporation rate with excellent light absorption remains a critical challenge in the structural regulation of evaporators. Herein, inspired by the natural transpiration process in plants (blue spruce), we designed a three-dimensional (3D) cone-shaped solar steam generator based on vertical polypyrrole nanowires-coated fabric (VPPyNWs-fabric). The microstructure design of polypyrrole (PPy) increases the solar energy absorption of the incident light through multiple reflections between the VPPyNWs, while the macrostructure design of the 3D evaporator possesses an enlarged surface area for energy harvesting, wide path for water supply, and open structure for vapor diffusion. As a proof of concept, the as-obtained 3D VPPyNWs-fabric-based solar steam generator demonstrates a fast water evaporation rate of 2.32 kg m-2 h-1 with high solar absorption of 97% and solar-to-vapor conversion efficiency of 98.56% at 1 kW m-2 energy density. In addition, the solar steam generator can be steadily applied in various water conditions, e.g., seawater, dye wastewater, and acidic and alkaline wastewater. This high-performance evaporator via 3D macro- and microstructure design offers a new avenue for better utilization of solar energy.