Multifunctional Materials最新文献

{"title":"Exchange stiffness influence on Terfenol-D magnetic states","authors":"Cai Chen, Brian D Fu, Marina E Dannecker, Rodrigo U Curiel, G. Carman, A. Sepulveda","doi":"10.1088/2399-7532/aadca5","DOIUrl":"https://doi.org/10.1088/2399-7532/aadca5","url":null,"abstract":"Terfenol-D has one of the largest magnetoelastic coefficients at room temperature, making it a good candidate for future magnetoelectric memory devices. However, few studies exist on the spin configuration in nanoscale Terfenol-D single domain structures. There are two exchange stiffness parameters of Terfenoal-D reported in the literature. In this paper, we use micromagnetic simulations to evaluate the influence of these two exchange parameters on the spin states of ellipsoidal shapes. Analytical results indicate that these two parameters produce significantly different spin states. Therefore, experiments to more accurately measure the exchange stiffness constant of Terfenol-D are needed.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aadca5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41531505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional fibers for robotic fabrics","authors":"Trevor L. Buckner, Rebecca Kramer‐Bottiglio","doi":"10.1088/2399-7532/aad378","DOIUrl":"https://doi.org/10.1088/2399-7532/aad378","url":null,"abstract":"Fabrics have conventionally been passive materials with static properties, leveraging the mechanical, optical, and thermal properties of networks of fibers. Recently, however, the emergence of functional fibers with dynamic properties has begun to disrupt this conventional definition. Engineers have begun to explore new materials and manufacturing processes for actuating, sensing, and variable-stiffness fibers, and the integration of these functional fibers into dynamic, robotic fabrics. This review discusses recent developments in functional fibers and speculates on their utility in future robotic fabrics.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aad378","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45073597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphitic microstructure and performance of carbon fibre Li-ion structural battery electrodes","authors":"G. Fredi, S. Jeschke, Athmane Boulaoued, J. Wallenstein, M. Rashidi, Fang Liu, R. Harnden, D. Zenkert, J. Hagberg, G. Lindbergh, P. Johansson, L. Stievano, L. Asp","doi":"10.1088/2399-7532/aab707","DOIUrl":"https://doi.org/10.1088/2399-7532/aab707","url":null,"abstract":"Carbon fibres (CFs), originally made for use in structural composites, have also been demonstrated as high capacity Li-ion battery negative electrodes. Consequently, CFs can be used as structural electrodes; simultaneously carrying mechanical load and storing electrical energy in multifunctional structural batteries. To date, all CF microstructural designs have been generated to realise a targeted mechanical property, e.g. high strength or stiffness, based on a profound understanding of the relationship between the graphitic microstructure and the mechanical performance. Here we further advance this understanding by linking CF microstructure to the lithium insertion mechanism and the resulting electrochemical capacity. Different PAN-based CFs ranging from intermediate- to high-modulus types with distinct differences in microstructure are characterised in detail by SEM and HR-TEM and electrochemical methods. Furthermore, the mechanism of Li-ion intercalation during charge/discharge is studied by in situ confocal Raman spectroscopy on individual CFs. Raman G band analysis reveals a Li-ion intercalation mechanism in the high-modulus fibre reminiscent of that in crystalline graphite. Also, the combination of a relatively low capacity of the high-modulus CFs (ca. 150 mAh g−1) is shown to be due to that the formation of a staged structure is frustrated by an obstructive turbostratic disorder. In contrast, intermediate-modulus CFs, which have significantly higher capacities (ca. 300 mAh g−1), have Raman spectra indicating a Li-ion insertion mechanism closer to that of partly disordered carbons. Based on these findings, CFs with improved multifunctional performance can be realised by tailoring the graphitic order and crystallite sizes.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aab707","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44045421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reversible shape change structures by grayscale pattern 4D printing","authors":"Jiangtao Wu, Zeang Zhao, Xiao Kuang, Craig M. Hamel, D. Fang, H. Qi","doi":"10.1088/2399-7532/aac322","DOIUrl":"https://doi.org/10.1088/2399-7532/aac322","url":null,"abstract":"Structures and devices with reversible shape change (RSC) are highly desirable in many applications such as mechanical actuators, soft robotics, and artificial muscles. In this paper, we propose to use 3D grayscale printing method to create reversible self-folding structures. The grayscale pattern was used to control the light intensity distribution of a UV projector in a digital light processing 3D printer such that the same photo irradiation time leads to different curing degrees and thus different crosslinking densities at different locations in the polymer during 3D printing. After leaching the uncured oligomers inside the loosely crosslinked network, bending deformation could be induced due to the volume shrinkage. The bending deformation was reversed if the bent structure absorbed acetone and swelled. Using this method, we designed and created RSC structures such as reversible pattern transformation and self-expanding/shrinking structures, auxetic metamaterial, structures mimicking the blossom of a flower. The grayscale 4D printing method provides us a simple and efficient way to create active structures and has great potential in the application of smart structures, composite materials, soft robotics and endovascular stent.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aac322","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45990549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microporous electrostrictive materials for vibrational energy harvesting","authors":"Mickaël Pruvost, W. J. Smit, C. Monteux, P. Poulin, A. Colin","doi":"10.1088/2399-7532/aab2ff","DOIUrl":"https://doi.org/10.1088/2399-7532/aab2ff","url":null,"abstract":"We present electrostrictive materials with excellent properties for vibrational energy harvesting applications. The developed materials consist of a porous carbon black composite, which is processed using water-in-oil emulsions. In combination with an insulating layer, the investigated structures exhibit a high effective relative dielectric permittivity (up to 182 at 100 Hz) with very low effective conductivity (down to 2.53 10−8 S m−1). They can generate electrical energy in response to mechanical vibrations with a power density of 0.38 W m−3 under an applied bias electric field of 32 V. They display figures or merit for energy harvesting applications well above reference polymer materials in the field, including fluorinated co- and ter-polymers synthetized by heavy chemical processes. The production process of the present materials is based on non hazardous and low-cost chemicals. The soft dielectric materials are highly flexible (Young’s modulus of ∼1 MPa) making them also suited for highly sensitive capacitive sensors.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aab2ff","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47078135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional materials: concepts, function-structure relationships, knowledge-based design, translational materials research","authors":"A. Lendlein, R. Trask","doi":"10.1088/2399-7532/aada7b","DOIUrl":"https://doi.org/10.1088/2399-7532/aada7b","url":null,"abstract":"Integrating different functions in one material system is a fundamental challenge, especially if those functions seem to exclude each other. Understanding function-structure relationships and developing a competence in the system approach for multifunctionality enables many modern applications, which can improve quality of life and address important global challenges. The interdisciplinary field recently extends to computational engineering approaches for virtual material design and to advanced fabrication schemes taking advantage of digitalisation. In this way development cycles can be shortened and products based on multifunctional materials can become more and more adaptive and individualised. It is against this backdrop that Multifunctional Materials has been launched, in consultation with the scientific community, to become a selective journal focused on conceptual novelty that will uniquely bring together all aspects of this rapidly developing field.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"55 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aada7b","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41246678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional hyperuniform cellular networks: optimality, anisotropy and disorder","authors":"S. Torquato, D. Chen","doi":"10.1088/2399-7532/aaca91","DOIUrl":"https://doi.org/10.1088/2399-7532/aaca91","url":null,"abstract":"Disordered hyperuniform heterogeneous materials are new, exotic amorphous states of matter that behave like crystals in the manner in which they suppress volume-fraction fluctuations at large length scales, and yet are statistically isotropic with no Bragg peaks. It has recently been shown that disordered hyperuniform dielectric two-dimensional (2D) cellular network solids possess complete photonic band gaps comparable in size to photonic crystals, while at the same time maintaining statistical isotropy, enabling waveguide geometries not possible with photonic crystals. Motivated by these developments, we explore other functionalities of various 2D ordered and disordered hyperuniform cellular networks, including their effective thermal or electrical conductivities and elastic moduli. We establish the multifunctionality of a class of such low-density networks by demonstrating that they maximize or virtually maximize the effective conductivities and elastic moduli. This is accomplished using the machinery of homogenization theory, including optimal bounds and cross-property bounds, and statistical mechanics. We rigorously prove that anisotropic networks consisting of sets of intersecting parallel channels in the low-density limit, ordered or disordered, possess optimal effective conductivity tensors. For a variety of different disordered networks, we show that when short-range and long-range order increases, there is an increase in both the effective conductivity and elastic moduli of the network. Moreover, we demonstrate that the effective conductivity and elastic moduli of various disordered networks derived from disordered ‘stealthy’ hyperuniform point patterns possess virtually optimal values. We note that the optimal networks for conductivity are also optimal for the fluid permeability associated with slow viscous flow through the channels as well as the mean survival time associated with diffusion-controlled reactions in the channels. In summary, we have identified ordered and disordered hyperuniform low-weight cellular networks that are multifunctional with respect to transport (e.g., heat dissipation and fluid transport), mechanical and electromagnetic properties, which can be readily fabricated using 3D printing and lithographic technologies.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aaca91","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41795694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of fabrication parameters on the electrochemical performance of multifunctional structural supercapacitors","authors":"Guocheng Qi, S. Nguyen, D. B. Anthony, A. Kucernak, M. Shaffer, E. Greenhalgh","doi":"10.1088/2399-7532/ac1ea6","DOIUrl":"https://doi.org/10.1088/2399-7532/ac1ea6","url":null,"abstract":"Multifunctional structural supercapacitors based on carbon fibre electrodes (CF) and structural electrolytes (SEs) can realise multifunctionality by simultaneously bearing load and providing electrochemical energy storage. Structural supercapacitor constituents (i.e. electrodes and electrolytes) have undergone significant development to enhance their electrochemical and mechanical properties. However, the fabrication of fully functional devices presents a number of practical challenges to achieve optimal multifunctional properties, particularly those associated with assembly and lamination. This work investigated the effect of separator selection and processing parameters on the electrochemical performance of structural supercapacitors, as well as evaluating the repeatability of the SE filming process. Two layers of glass fibre fabrics were the most effective separator for preventing short-circuiting of the structural supercapacitors. The weight fraction of the SE matrix had a significant effect on the capacitance, energy and power of the structural supercapacitors. By addressing such fabrication challenges, high performance structural supercapacitors can be manufactured with greater reproducibility and at larger scales such that they are suitable for integration in industrial applications.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61174069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}