High Absorption Efficiency Research Articles

Integrated design of MOFs-derived 0D/1D/2D/3D hierarchical network for high-efficiency electromagnetic wave absorption

To overcome electromagnetic pollution issues, multi-dimensional carbon-magnetic composites have gained attention. In this study, a 2D nanosheets stacked 3D network with 0D Co particles and 1D CNTs was synthesized via hydrothermal and annealing method. The nitrogen-doped porous 3D crosslinked network constructed with intertwined 1D and 2D components (CNTs, PDA-derived carbon, and MOFs-derived carbon) effectively extends the propagation pathway, providing superior conductive loss. Moreover, the 3D magnetic-electrical porous heterostructure greatly enhances the multiple scattering and reflection of the incident waves, as well as induces excellent eddy current loss. In addition, 0D Co nanoparticles exhibit multi-mode magnetic resonances and optimize impedance matching characteristics to capture more electromagnetic waves (EMWs). The microstructures, consisting of rich defects and multilevel heterogeneous interfaces, stimulate multidimensional advantages to regulate relaxation time for optimized dipolar polarization and interface polarization. Consequently, the multidimensional Co/CNTs@C heterostructure displays an optimum absorption of −59.1 dB at 11.3 GHz (loading of 10 wt%) and an ultra-width effective absorption band (EAB) of 8.1 GHz (20 wt%). Relevant simulation experiments demonstrate the strong absorption and extremely poor reflection, testifying its surprising performance. Overall, this work provides a novel strategy for preparing MOFs-derived multidimensional EMW absorbing materials.

Development of high performance microwave absorption modified epoxy coatings based on nano-ferrites

With the rapid spread of wireless technologies and increasing electromagnetic energy, electromagnetic waves (EMW) have become a severe threat to human health. Therefore, minimizing the harmful effects of electromagnetic wave radiation is possible through the development of high-efficiency EMW absorption coatings. The aim of this work was to generate microwave absorbance coatings containing synthesized nano-CuFe2O4 and nano-CaFe2O4. Firstly, nano-CuFe2O4 and nano-CaFe2O4 were synthesized using the sol–gel method. Then, their structure, electrical, dielectric, and magnetic properties were investigated to find out the possibility of using these materials in high-frequency applications (e.g., microwave absorbance coatings). After that, two dosages (2.5 wt% and 5 wt%) of nano-CuFe2O4 and nano-CaFe2O4 were incorporated into epoxy resin to prepare modified epoxy resin as microwave coatings. The dielectric studies show that the AC conductivity of the prepared samples is high at high frequencies. Additionally, the magnetic properties reveal a low coercivity value, making these samples suitable for high-frequency devices. The microwave results illustrate that adding nano-ferrites with high content enhances the absorption characteristics of the tested films. The results showed that the two films have two absorption bands with RL < –10 dB ranging from 10.61 to 10.97 GHz and from 10.25 to 11.2 GHz. The minimum return loss achieved for the two cases is −13 and −16 dB, respectively. Indicating that the film coated with CuFe has a better absorption value than the one coated with CaFe.

Multispectral MoSi superconducting nanowire single photon detector

In this paper, a multispectral superconducting nanowire single photon detector (SNSPD) with high absorption efficiency is designed. It consists of Ag reflector, two SiO layers, Si slot and MoSi nanowire. Considering two typical quantum communication wavelengths (1310 nm and 1550 nm), when filling factor is 30 %, numerical simulation results show that the absorption efficiency of SNSPD can be over 95 % at each wavelength separately, and over 86 % at two target wavelengths simultaneously after introducing the second SiO layer and adjusting the structure parameters. And when filling factor is set to 40 %, the results at two target wavelengths are over 93 % and a broadband absorption (>80 %) of 1140 nm–1600 nm appears. In addition, the polarization sensitivity of the two-SiO-layers SNSPD is analyzed. When filling factor is over 63 %, the SNSPD attains both high absorption efficiency and TM-TE polarization insensitivity at two target wavelengths. The results of this work may provide access to fabricate high-efficiency and multispectral SNSPDs, and find applications in quantum optics and quantum communication systems.

Energy absorption characteristics of stepped multi-cell columns subjected to transverse loading

Automotive bumper beam is a vital component that shields passenger and vehicle from harm and damage generated by catastrophic collapse. Previous investigations on its bending behavior have largely concentrated on multi-cell tubes with the same length, whereas stepped multi-cell structures have received less attention. In this paper, a novel stepped multi-cell configuration is proposed to improve the energy absorption characteristics of thin-walled structures under transverse loading. The finite element method is employed to analyze the crushing behaviors of the stepped multi-cell tubes. The numerical results reveal that the stepped multi-cell structures (SM2 to SM5) can reduce the initial peak force by 23.44–45.91% while increasing the energy absorption capacity, crush load efficiency, and specific energy absorption by 5.87–29.51, 38.29–139.45, and 5.87–29.51%, respectively, when compared to a conventional square tube (M1). In addition, the effects of wall thickness, section width, load angle, punch radius, and punch shape on the bending behaviors and energy absorption characteristics are examined. The results indicate that these factors have a considerable influence on the deformation features of M1 and SM2, which leads to a significant reduction in their bending energy absorption characteristics. These variables have no influence on the deformation modes of SM3, SM4, and SM5, and they present local indentation deformation with a high energy absorption efficiency. Increasing the number of layers improves the comprehensive performance of stepped multi-cell tubes, with SM5 exhibiting the best energy absorption characteristics under transverse loading.

The effect of hydroxychloroquine on cholesterol synthesis depends on the profile of cholesterol metabolism. A controlled clinical study

Background and aimsHydroxychloroquine (HCQ) has a variable effect on cholesterol synthesis. To clarify this, we assessed the effect of HCQ on the cholesterol-synthesis pathway in individuals with low and high cholesterol absorption efficiency. MethodA total of 53 acute myocardial infarction patients with a constant statin dose randomized to receive HCQ or placebo for six months in a double-blind manner, were classified further into low (n = 26) and high (n = 27) cholesterol absorbers based on the median baseline serum cholestanol level. Serum lipids and biomarkers of cholesterol synthesis (squalene, lanosterol, zymostenol, desmosterol, and lathosterol) and absorption efficiency (sitosterol and cholestanol), were measured at baseline and one-, six-, and 12-month follow-up visits. ResultsIn low cholesterol absorbers, serum cholesterol concentration and cholesterol synthesis and absorption biomarkers did not differ between the HCQ and placebo groups. At one month, high cholesterol absorbers with HCQ had lower serum cholesterol concentration and serum lanosterol to cholesterol ratio in comparison to the placebo group (HCQ 3.18 ± 0.62 vs. placebo 3.71 ± 0.65, p = 0.042, and HCQ 10.4 ± 2.55 vs. placebo 13.1 ± 2.36, p = 0.008, respectively). At 12 months, serum desmosterol to cholesterol ratio was lower in HCQ users (HCQ 47.1 ± 7.08 vs. placebo 59.0 ± 13.1, p = 0.011). ConclusionsHCQ affects the cholesterol-synthesis pathway in high cholesterol absorbers. It reduces serum lanosterol and desmosterol ratios and consequently serum cholesterol concentration possibly by inhibiting the activity of lanosterol synthase as described earlier in vitro studies. Trial registrationClinicalTrials.gov Identifier: NCT02648464.

High-efficiency electromagnetic wave absorption of lightweight Nb2O5/CNTs/polyimide with excellent thermal insulation and compression resistance integration

With the widespread application of electronic devices, multifunctional electromagnetic wave (EMW) absorbing materials suitable for complex high-temperature and high-pressure environments, have attracted tremendous research attention. Herein, multifunctional polyimide (PI) composites doped with fluffy Nb2O5/CNTs microspheres (NBCP) were prepared by combining the ultrasonic spraying process and freeze-drying technique. Introduction of fillers results in the formation of diverse conduction paths and heterogeneous interfaces, which enhance the dielectric loss. Furthermore, the multi-porous structure of the PI matrix induces multiple reflection scattering events and improves the impedance matching. Such a multi-loss mechanism endows NBCP with an excellent EMW absorption performance. At 15 vol% filling, the minimum reflection loss is −41.66 dB, the effective absorption bandwidth is 2.63 GHz, and the radar cross-section is reduced by 85%. Furthermore, NBCP exhibits outstanding mechanical properties and a thermal insulation of over 100 °C in thermal environment at 150 °C. The proposed multifunctional NBCP is thus an efficient EMW absorber that offers significant potential for applications in harsh environments.

Revisiting the Optoelectronic Properties of Graphene: A DFT Approach

Understanding the atomic behaviour of pure graphene is crucial in manipulating its properties for achieving optoelectronics with high absorption indexes and efficiencies. However, previous research employing the DFT approach emphasised its zero-band gap nature, not its unique optical properties. Therefore, this study employed ab initio calculations to revisit the electronic, magnetic, and optical properties of pristine graphene using the WIEN2K code. The results reveal that the PBE-GGA valence and conduction bands cross at -0.7 eV. Our calculations demonstrated that the absorption coefficient of graphene has the strongest light penetration in the parallel direction. Furthermore, our results not only present the best possible propagation of light in pure graphene but also reveal that the linear relationship between the formation of the free electron carriers and the energy absorption is responsible for the high optical conductivity observed in pure graphene, as indicated by the peaks. Lastly, the metallic properties of graphene are reflected by the variation in spin up and down that appears, as evidenced by the total and partial densities of states, and the large refractive index attributed to its high electron mobility confirms its metallic nature.

Insight into lightweight MXene/Polyimide aerogel with high-efficient microwave absorption

Two-dimensional transition metal carbides and nitrides (MXenes) which enriched with surface functional groups, defects, and considerable interlayer spaces, demonstrate promising prospects in microwave absorption due to that significantly contribute to dielectric loss. However, their limited gelation ability in aqueous solutions and propensity for self-stacking restrict their applications. Addressing this, a lightweight Ti3C2Tx MXene/Polyimide (MP) aerogel nanocomposites without magnetic materials has been developed through a straightforward freeze-drying method, where ‘PI chains’ anchor the MXene layers, inhibiting self-stacking and enhancing interactions between the Ti3C2Tx nanosheets. The prepared composite aerogels with different MXene contents exhibit exceptional microwave absorption performance. When the thickness of the MP30% is 1.92 mm, the minimum reflection loss (RLmin) is −49.36 dB at 16.28 GHz, and the effective absorption bandwidth (EAB) reaches 6.9 GHz with a matching thickness of 2.5 mm. At 3.8 mm, MP45% achieves an RLmin of −80.4 dB. Additionally, MP aerogels have a notable role in fire protection and insulation. The microwave absorbing mechanism of lightweight MP aerogels from the perspectives of chemical composition and physical structure was deeply explored, which is helpful to the preparation of MXene/PI based aerogels with better microwave absorbing ability in the future. Furthermore, the radar cross section (RCS) reduction value of the optimized MP30% aerogel is simulated as high as 34.775 dBm2 when the scattering angle is 90o using the computer simulation technology (CST). The prepared MP aerogel with extraordinary radar attenuation ability could potentially be applied as efficient absorber candidates in practical applications.

Watermelon pulp biochar decorated with Co3Fe7 for high-efficiency electromagnetic wave absorption

Bio-char decorated with inorganic magnetic component has shown great potential as a microwave absorbent because of the synergistic effect of two components. This composite holds promising prospects for applications in both military and civilian sectors. However, the composition and structure design of magnetic material/bio-char composites is still a challenge. Herein, the Co3Fe7/watermelon pulp biomass carbon (WPC) composite was designed. CoFe2O4 was converted into Co3Fe7 when co-calcined with pre-treated watermelon pulp (PWP). The EAB of Co3Fe7/WPC reaches 6.00 GHz at the thickness of 2 mm. The results show that this exceptional absorption performance of Co3Fe7/WPC is owed to its optimal impedance matching, multiple polarization and superior conductive loss. This work provides reference value for the preparation strategy of sustainable high-efficiency electromagnetic wave absorbing materials.

Strong microwave absorption performance of simply grinding FAPbI3/CNTs composite absorbers

The distinctive physical and chemical characteristics of organic-inorganic lead halide perovskite make it a promising candidate for microwave absorption applications. However, the high-efficiency microwave absorption of halide perovskite-based composites is concentrated at high frequencies, while electronic equipment operates at low-frequency bands. Exploring simple and efficient methods to achieve optimal microwave absorption efficiency at low frequencies continues to pose a considerable challenge. Here, FAPbI3 was synthesized by a simple solvent-free hand grinding method and mixed with carbon nanotubes (CNTs) to obtain a series of FAPbI3/CNTs (FC) composites. By modulating the mass ratio of the components, FAPbI3 modulates the absorption bands, CNTs can effectively establish a conductive network to enhance both polarization loss and conductive loss and regulate impedance matching. The lower permittivity of FAPbI3 gives FC an advantage in terms of low-frequency microwave absorption. The FC-4 composite exhibits a minimum reflection loss (RLmin) of −55.67 dB at a low frequency of 6.88 GHz with a thickness of 3.5 mm. Meanwhile, microwave absorption performance can reach 99 % covering almost the entire C band when utilizing a thickness ranging from 3 to 5 mm. Additionally, according to adjusting the load of FAPbI3 in the mixture, the FC-3 composite displays the highest microwave absorption value among the composites based on halide perovskites. With a thickness of 1.4 mm, the reflection loss at 17.4 GHz reaches an impressive minimum value of −71.89 dB. This study represents the first research specifically focused on FAPbI3 perovskite in the domain of microwave absorption. FC composites display remarkable capabilities in absorbing microwaves, indicating their promising prospects for advancement within the realm of microwave absorption. This research may provide valuable insights for the design of low-frequency and high-efficiency microwave absorbers.

Heterointerface regulation of core-shell FeSiAl magnetic powders by in situ oxidation as high-efficiency absorbers

Developing electromagnetic (EM) absorbers that are highly efficient across a wide bandwidth is a significant hurdle in mitigating the growing issue of EM pollution emanating from the increasing prevalence of electronic and telecommunication devices. When considering the applications of absorbers in high-temperature environment, ensuring both structural and chemical stability becomes crucial. Incorporating a magnetic core and dielectric shell within core-shell structures appears to be a promising strategy for addressing this challenge. In this work, we have successfully synthesized the core-shell FeSiAl@oxide composites through in situ oxidation process, which offers a facile route for significantly enhancing their EM absorbing performance by promoting multiple interfacial polarizations and achieving ideal impedance matching. A systematic analysis has been conducted to uncover the morphological and microstructural evolution of the FeSiAl@oxide composites, shedding light on their EM properties. The remarkable EM dissipation capacity of these composites, owing to the strong synergistic effects between magnetic and dielectric losses, has been demonstrated with the minimum absorption of −41.7 dB over an impressive absorption bandwidth of 7.92 GHz at 2.5 mm.

Theoretical and experimental investigation on the sound absorption performance of ultra-thin curled acoustic metasurface

A simplified model of the absorption coefficient of traditional Helmholtz resonators (THR) was established, and the influence of different geometric parameters on the absorption coefficient of THR was analyzed. To realize the low-frequency broadband acoustic structure design, an accurate theoretical model for the sound absorption coefficient of the curled acoustic metasurface (CAM) unit was established. Based on the complex frequency plane method (CFPM), the CAM units with perfect sound absorption at four discrete frequencies were designed. The low-frequency broadband acoustic metasurfaces in parallel under decoupled and coupled conditions were studied, and the thickness is only 12 mm. The high efficiency of sound absorption above 0.8 was achieved in the frequency range of 758 Hz–940 Hz. The experiment verifies the efficient sound absorption effect of the CAM unit and the broadband sound absorption effect under coupled conditions. The research in this paper has a certain potential applications for low-frequency broadband noise control technology.

A combined engineering of hollow and core-shell structures for C@MoS2 microcapsules toward high-efficiency electromagnetic absorption

Rational design of profitable structure is widely considered as an effective strategy for electromagnetic wave absorbing materials (EWAMs) to improve their performance. Herein, we conduct a combined engineering of hollow and core-shell structures, in which surface shell is formed by a number of MoS2 nanosheets crossing each other and internal core is hollow carbon microcapsule (HC). HC has strong dielectric loss ability, and its hollow structure facilitates the multiple reflection of incident EM wave. The construction of MoS2 shells not only improves impedance matching but also introduces heterogeneous interfaces that result in interfacial polarization loss. It is found that the synergistic effect of intrinsic loss mechanisms and structural advantages endow C@MoS2 composites (HCM-x) with excellent EM wave absorption performance, and especially for HCM-2, whose minimum reflection loss (RL) intensity and effective absorption bandwidth (EAB) are −63.8 dB and 6.0 GHz, respectively. It is believed that this work is valuable for the enhancement of performance for EWAMs through the upgrade of microstructure and regulation of chemical composition.

The profile of cholesterol metabolism does not interfere with the cholesterol-lowering efficacy of phytostanol esters

Increasing evidence suggests that high cholesterol absorption efficiency enhances the risk of atherosclerotic cardiovascular diseases. It is not known whether inhibiting cholesterol absorption has different metabolic effects in high- vs. low cholesterol absorbers. We evaluated the effects of phytostanol esters on serum lipids and cholesterol metabolism in a post hoc study of three randomized, double-blind, controlled trials. The participants were classified into low (n=20) and high (n=21) cholesterol absorbers by median cholesterol absorption efficiency based on the plasma cholesterol absorption marker cholestanol at baseline. The participants consumed mayonnaise or margarine without or with phytostanol esters for six to nine weeks without other changes in the diet or lifestyle. Serum cholesterol, cholestanol, lathosterol, and faecal neutral sterols and bile acids were analysed by gas-liquid chromatography. According to power calculations, the size of the study population (n=41) was appropriate. During the control period, cholesterol synthesis, and faecal neutral sterols and bile acids were lower in high- vs. low absorbers (p<0.05 for all). Phytostanol esters reduced low-density lipoprotein cholesterol by 10-13% in both groups, and directly measured cholesterol absorption efficiency by 41±7% in low- and 47±5% in high absorbers (p<0.001 for all) without side effects. Cholesterol synthesis and faecal neutral sterols (p<0.01) increased in both groups, more markedly in the high vs. low absorbers (p<0.01). Low cholesterol absorption combined with high faecal neutral sterol excretion are components of reverse cholesterol transport. Thus, high- vs. low absorbers had a more disadvantageous metabolic profile at baseline. In both groups, phytostanol esters induced favourable changes in serum, lipoprotein, and metabolic variables known to help in prevention of the development of atherosclerotic cardiovascular diseases.

Dynamic H-Bond crosslinking strategy to prepare impact-hardening protective materials with tunable negative Poisson's ratio

Protective materials with a wide range of practical applications should exhibit a high energy absorption efficiency and be smart and stress-responsive. Herein, a novel smart protective material was formed from an impact-hardening polymer (IHP), which comprised a branched structure, and polyurethane (PU) with quadruple H-bonding. Notably, the quadruple H-bonding was used to enhance the interaction between the two microphases, thus regulating the negative Poisson's ratio. The value of the reversible softness–stiffness switching effect of this material (UPy-IHP-PU) achieved more than 5000, five times stronger than that of a previously reported linear IHP-PU. In addition, the impact-protective ability did not weaken. As the impact velocity increased, the impact energy absorption efficiency of UPy-IHP-PU also increased, even exceeded 70 % under the impact velocity of 5 m/s, thus demonstrating the ability to efficiently reduce the impact force and extend the buffer time against the strike via the impact-hardening phenomenon. Moreover, an adjustable scale of microphase separation can regulate the negative Poisson's ratio to enhance the impact-hardening phenomenon. The excellent energy dissipation ability and smart stress- and rate-responsiveness indicate the application potentials of UPy-IHP-PU as a future wearable impact-protective sensor.

An efficient fabrication method of lightweight aramid nanofibrous aerogels for high-efficient sound absorption and thermal properties

The aramid nanofibrous aerogels (ANFs) have various application prospects due to their ultra-light, high porosity and excellent properties of aramid fibers. However, the preparation of ANFs requires long preparation time and their ultra-dense pore structure leads to poor sound penetration and high sound energy reflectivity, which ultimately makes the overall sound absorption performance of ANFs poor. Therefore, a strategy for synthesis of ANFs is designed to achieve light weight, excellent thermal insulation performance and significantly improve sound absorption properties. This strategy combines cell pulverizing, pump-filtration molding, and directional freezing to ensure structural strength of the aerogel without the addition of cross-linking agents, and this process enables the ANFs to introduce in macro-pores while keeping nano-pores. The structure of multi-layered pores effectively reduces the reflectivity of incident acoustic energy and improves the sound absorption coefficient. The interconnected macro-pores and interlaced small pores of ANFs provide good sound absorption performance (sound absorption average (SAA) = 0.338), excellent flame retardant and thermal insulation properties (thermal conductivity = 0.0635 W (m*K)−1) with ultralight (density = 40.5 mg cm−3) in a thinner thickness (15 mm), which extend the potential of ANFs in areas of noise control and thermal insulation. In addition, the structure of multi-scaled pores can also be formed inside other aerogels by using the method of cell pulverization and filtration preparation, which can be helpful for improving their properties of thermal insulation and sound absorption.

The study of optical and electrical properties of AgInS2-based composite

sPhotovoltaic solar energy was one of the few sustainable and pollution-free energy sources. AgInS2 was a promising photovoltaic material, which had attracted considerable in long time due to its outstanding photovoltaic performance. Furthermore, the nanoparticles could improve the light absorption efficiency of absorption layer to enhance the photoelectric conversion efficiency of solar cell. In this paper, the suitable preparation methods of AgInS2 film and gold nanoparticles were used to improve the optical-electric performances of AgInS2-based solar cell. AgInS2 films were prepared by vacuum evaporation using different raw materials (Ag + In + S and Ag2S + In2S3) and then annealed at 400 °C or 425 °C. From absorption spectrum, the AgInS2 film, which was prepared by two components (Ag2S + In2S3) and annealed at 400 °C, had the highest absorption. And the transmission spectrum of the AgInS2 film was similar to that obtained from finite difference time domain simulation. Furthermore, this AgInS2 film was used to prepare AgInS2/CdS PN junction and AgInS2/gold/CdS PN junction. Due to the introduction of gold nanoparticles, the forward current of the AgInS2/gold/CdS PN junction increased an order of magnitude, but ideal factor and barrier height decreased, which meant that gold nanoparticles can promote carrier transport and improve electric property. As a result, this AgInS2/gold/CdS PN junction owned high absorption efficiency, low reverse saturation current and large barrier height, which meant huge application potential in solar cells field.

VOC absorption in supramolecular deep eutectic solvents: Experiment and molecular dynamic studies

The absorption of volatile organic compounds (VOCs) using supramolecular deep eutectic solvents (SUPRADES), composed of randomly methylated β-cyclodextrin (RAMEB) and conventional organic solvents, was systematically investigated from vapor-liquid experiments to molecular dynamic simulations. The obtained partition coefficients suggest that the combination of RAMEB and ethylene glycol (REG, mole ratio 1:40) significantly improves the absorption ability of ethylene glycol (EG), making REG even the most efficient absorbent for chloroform and limonene. By studying the key factors affecting the absorption process, we found that increasing the concentration of VOCs in the gas phase, lowering the absorption temperature or reducing the water content of the absorbent are effective in improving absorption. Regeneration test shows that the absorption ratio of chloroform using REG is maintained around 99% under six absorption–desorption cycles, highlighting its high absorption efficiency and stability. The absorption mechanism was then deeply explored by molecular dynamic simulation. It was found that the hydrogen bond between RAMEB and EG hinders the aggregation of neighboring RAMEB molecules, helping RAMEB to form stable and homogeneous solvent with EG. In addition, the interaction energy analysis demonstrates that van der Waals forces contribute the most to the absorption of chloroform by REG. Finally, the radical distribution function analysis was used to visualize the 2-dimensional molecule distribution of SUPRADES systems and the spatial distribution analysis verified the formation of RAMEB/chloroform inclusion complexes in the absorption process. The obtained results indicate that REG is a highly efficient and easy recyclable solvent for VOCs absorption.

Design and full analysis of a metafiber-based photothermal bio-probe with perfect conversion efficiency

The metafiber, which involves fabricating metasurfaces at optical fiber tips, has shown potential as an integrated optical sensing or photothermal conversion platform. In this study, we present a metafiber-based photothermal bio-probe with a high optical absorption efficiency of 99.83%. Physical mechanisms underlying the efficiency are elucidated using coherent perfect absorption and multiple reflection theories. In our simulation, the probe exhibits ultra-fast heating/cooling rates, high temperature localization, steep temperature gradients, and robust response to environmental factors. In particular, only 1.0 mW of incident power is needed to generate the temperature gradient required for cell capture or drug delivery, while the corresponding temperature near the fiber tip is still safe for biological tissue. These advantages make our designed bio-probe as an ideal platform in various of applications, such as living cells capture, drug delivery, and local hyperthermia.

Experimental and numerical study of in-plane uniaxial compression response of PU foam filled aluminum arrowhead auxetic honeycomb

PurposeAuxetics metamaterials show high performance in their specific characteristics, while the absolute stiffness and strength are much weaker due to substantial porosity. This paper aims to propose a novel auxetic honeycomb structure manufactured using selective laser melting and study the enhanced mechanical performance when subjected to in-plane compression loading.Design/methodology/approachA novel composite structure was designed and fabricated on the basis of an arrowhead auxetic honeycomb and filled with polyurethane foam. The deformation mechanism and mechanical responses of the structure with different structural parameters were investigated experimentally and numerically. With the verified simulation models, the effects of parameters on compression strength and energy absorption characteristics were further discussed through parametric analysis.FindingsA good agreement was achieved between the experimental and simulation results, showing an evidently enhanced compression strength and energy absorption capacity. The interaction between the auxetic honeycomb and foam reveals to exploit a reinforcement effect on the compression performance. The parametric analysis indicates that the composite with smaller included angel and higher foam density exhibits higher plateau stress and better specific energy absorption, while increasing strut thickness is undesirable for high energy absorption efficiency.Originality/valueThe results of this study served to demonstrate an enhanced mechanical performance for the foam filled auxetic honeycomb, which is expected to be exploited with applications in aerospace, automobile, civil engineering and protective devices. The findings of this study can provide numerical and experimental references for the design of structural parameters.