Article
Polymer Science
Yan Yu, Yan Zhao, Bin Huang, Yanwei Ji, Yunfeng Zhao, Zhijie Zhang, Hua- Feng Fei
Summary: This study investigates the effect of phenyl side groups on the dielectric properties of polysiloxane, and shows that introducing appropriate amount of phenyl side groups can improve the dielectric constant and electrical breakdown strength. The study also highlights the contribution of alpha- and beta-relaxations to the dielectric loss of the material.
Article
Polymer Science
Jie Mao, Jing Li, Wang Lin, Faliang Luo
Summary: This work presents a method for preparing a homogeneous polybutadiene dielectric elastomer with improved actuated strain using a photochemical thiol-ene click reaction. Different grafting groups are used on the polybutadiene, and the influence of polarity and hydrogen bonding effect on the dielectric and mechanical properties is discussed. The modified polybutadiene with butyl acrylate groups shows high dielectric constant, low dielectric loss, and large actuated strain.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Chemistry, Applied
Hongwei Pan, Zhaokun Wang, Yongyin Cui, Lan Cao, Chengzhong Zong
Summary: A novel ternary composite system was introduced, with rPGM conductive filler prepared by microwave reduction, resulting in NR composites with high elasticity and thermal resistance. The addition of rPGM significantly improved the electrical, mechanical, and thermal stability of the NR composites.
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
(2021)
Article
Polymer Science
Vitaliy G. Shevchenko, Gennady Stepanov, Elena Yu Kramarenko
Summary: The dielectric properties of two series of magnetoactive elastomers based on a soft silicone matrix with 35 vol% magnetic particles were experimentally studied. The presence of magnetically hard NdFeB filler allowed for passive control of the MAE dielectric response through sample magnetization. The transition from a non-conducting to a conducting state was more pronounced for hybrid MAEs containing both NdFeB and Fe particles with a tenfold size mismatch.
Article
Physics, Applied
Guangxiu Liu, Long Zhou, Bowen Zhou, Xubin Ye, Dabiao Lu, Xudong Shen, Shijun Qin, Zhiwei Hu, Yi-Ying Chin, Hong-Ji Lin, Chien-Te Chen, Xiaohui Yu, Youwen Long
Summary: The A-site ordered but B-site disordered quadruple perovskite oxide PbMn3Cr3MnO12 was synthesized using high-pressure and high-temperature methods. The compound shows three antiferromagnetic phase transitions at approximately 155K, 81K, and 74K, respectively, due to complex spin interactions. Introducing Mn4+ ions into the B site increases the A-site spin-related ordering temperature significantly.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Rui Peng, Liang Shi, Yongcheng Lu, Xiaolei Shi, Gang Wang, Yuanxun Li, Hua Su, Daming Chen, Yuanzheng He
Summary: This study investigated the sintering and dielectric properties of (1 - x)Li2Mg0.95Co0.05SiO4 + xTiO(2) ceramics synthesized by the solid state reaction method. The addition of TiO2 was found to improve the grain size, sintering properties, dielectric properties, and relative density of the ceramics.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Chemistry, Multidisciplinary
Hayden E. Fowler, Philipp Rothemund, Christoph Keplinger, Timothy J. White
Summary: The integration of soft, stimuli-responsive materials in robotic systems allows for delicate object manipulation. Electrical control of mechanical response in liquid crystal elastomers (LCEs) results in rapid deformation with little hysteresis. The directional expansion and shape transformation capabilities of LCE actuators demonstrate promising applications in robotics.
ADVANCED MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Luca Ciarella, Andreas Richter, E. -F. Markus Henke
Summary: This article presents a multi-functional device made entirely of dielectric elastomers, which is controlled by a network of actuators and sensors through an electrical circuit. The device only requires a constant power supply to work and can produce its controlling signals. Every component of the device can be manufactured simultaneously with the same materials and processes.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Raja Annapooranan, Yang Wang, Shengqiang Cai
Summary: In this work, a new class of dielectric elastomer actuators using liquid crystal elastomers (DLCEs) is reported. The soft elasticity of DLCEs and their high dielectric constant are utilized to reduce actuation voltage. Freestanding DLCE thin film actuators are fabricated, which generate large actuation strains at a significantly lower input voltage compared to typical dielectric elastomers actuators. This allows for the development of a soft tunable bilayer DE lens with a 21% focal length variation.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Composites
Omid Aghababaei Tafreshi, Zia Saadatnia, Shahriar Ghaffari-Mosanenzadeh, Tianhao Chen, Sophie Kiddell, Chul B. Park, Hani E. Naguib
Summary: This study presents the fabrication of novel polyimide composite aerogel films with tunable dielectric properties by incorporating graphene nanoplatelet fillers. The addition of graphene improved the nanostructure of aerogels, resulting in improved homogeneity and uniformity of the composite gel films. The inclusion of graphene nanoplatelets proved to be an effective strategy for improving the mechanical properties, machinability, and thermal stability of aerogels.
COMPOSITES COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Yauhen Sheima, Johannes von Szczepanski, Patrick M. Danner, Tina Kuenniger, Arndt Remhof, Holger Frauenrath, Dorina M. Opris
Summary: Polysiloxanes modified with amide groups are found to exhibit high dielectric permittivity and fast recovery of initial shape. These elastomers have high strain at break and low mechanical loss factor, making them suitable for actuators and sensors with reliable performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Yan Yu, Bin Huang, Yan Zhao, Yunfeng Zhao, Lina Dai, Zhijie Zhang, Hua-Feng Fei
Summary: Polysiloxane-based dielectric elastomers have great potential as electroactive soft materials, but their low permittivity has hindered practical applications. This study demonstrates that introducing cyanosilicone oil into the elastomer matrix can significantly increase the permittivity and enhance the dielectric relaxation processes. The resulting elastomer composites exhibit lower Young's modulus and dielectric loss.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Yurong Zhang, Haidan Lin, Kai Dong, Shasha Tang, Chengji Zhao
Summary: A series of epoxy resins containing trifluoromethyl groups were synthesized and cured with diaminodiphenylmethane (DDM) and aminophenyl sulfone (DDS). The epoxy resins exhibited excellent thermal stability, with high glass transition temperatures and weight loss temperatures. DDS-cured epoxy resins had higher thermal stability, while DDM-cured epoxy resins showed better mechanical, dielectric, and hydrophobic properties. The results suggest that incorporating trifluoromethyl pendant groups into epoxy resins can improve their dielectric and hydrophobic performance.
Article
Chemistry, Inorganic & Nuclear
Wugang Lai, Yuanming Lai, Zhouyang Wei, Zan Jiao, Junjie Yu, Peicheng Yang, Ning Ding, Fangyi Huang, Fanshuo Wang, Meng Wei
Summary: In this study, Mg2-xLi2xAl4Si5O18 ceramics were synthesized and their phase composition, crystal structure, and microwave dielectric properties were investigated. The addition of Li2O influenced the densification of the samples, while the relative density and second phase determined the dielectric constant. The densification and packing fraction affected the Qf value, while the second phase and bond valence of the Mg-site determined the temperature coefficient of resonance frequency.
SOLID STATE SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Hao Zhong, Qiqi Xue, Jiameng Li, Yunfeng He, Yuxin Xie, Canhui Yang
Summary: In this paper, an all-solid electro-mechanically tunable lens driven by a dielectric elastomer actuator is presented. The tunable lens offers advantages in compactness, lightweight, low power consumption, and fast response compared to conventional lenses. The lens achieves a larger relative change of focal length than the human eye and exhibits fast response, stable operation, and long shelf-life.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Baihong Chen, Changyue Liu, Zengting Xu, Zhijian Wang, Rui Xiao
Summary: In this study, both polydomain and monodomain liquid crystal elastomers (LCEs) were synthesized and their shape change with temperature under a certain stress level was characterized. A thermo-order-mechanical coupling model was developed to predict the shape change of LCEs, showing good consistency with experimental results.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Peng Wang, Fei Xu, Yiding Wang, Jun Song, Cheng Chen
Summary: This study investigates the interplay of super-screw dislocations and coherent twin boundary (CTB) in Ni3Al using molecular dynamics simulations and dislocation continuum theory. Various interaction mechanisms are observed depending on the stress and dislocation gliding pathways. A continuum model framework is developed to evaluate the critical shear stress required for CTB to accommodate dislocations along different pathways, considering the effects of anti-phase boundary (APB) and Complex Stacking Fault (CSF). The study suggests that the resistant force of CTB against all gliding dislocations is a more appropriate metric for quantifying its strength.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Chenyu Du, Haitao Cui, Hongjian Zhang, Zhibin Cai, Weikuo Zhai
Summary: A thermal-elastoplastic phase field model was developed to simulate thermal fatigue crack growth. The accuracy and availability of the model were verified through typical examples. The results indicate that the proposed model effectively simulates the process of thermal fatigue crack propagation in elastoplastic solids. The appropriate regularization length needs to be determined based on experimental results.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
J. Carlsson, A. Kuswoyo, A. Shaikeea, N. A. Fleck
Summary: The sensitivity of the compressive strength of a polymeric Kelvin lattice to the presence of an epoxy core is investigated both experimentally and numerically. The study shows that the epoxy core prevents the formation of crush bands in the lattice and changes its deformation mode. At finite strain, the strength of the lattice is degraded by bending failure and cracking of the struts and adjacent core, leading to the formation of vertical fissures.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Saptarshi Paul, Anurag Gupta
Summary: In this study, we investigate the geometry and mechanics of the buckled orthotropic von Karman elastic plate with free boundary condition, in the presence of an isolated positive or negative disclination. The shape of the buckled plate is cone-like for a positive disclination and saddle-like for a negative disclination. With increasing orthotropy, the shape of the buckled plate becomes more tent-like and the Gaussian curvature spreads along the ridge of the tent. The stress fields are focused in the neighborhood of the defect point and the ridge, indicating that most of the stretching energy is accommodated in these singular regions.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Antu Acharya, Vikram Muthkani, Anirvan DasGupta, Atul Jain
Summary: This study proposes filler-based and infill-based strategies for creating auxetic lattices with enhanced stiffness. The elastic properties of the sinusoidal re-entrant honeycomb lattice are developed and validated using finite element models. Parametric studies are conducted to find combinations leading to enhanced stiffness with minor loss in auxeticity. The results demonstrate the possibility of achieving a significant increment in stiffness while retaining significant auxeticity. The proposed approaches outperform existing approaches in terms of stiffness and auxeticity.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Biswajit Pal, Ananth Ramaswamy
Summary: This study presents a multi-scale approach to simulate the shrinkage and creep of concrete, addressing the limitations of existing macroscopic prediction models due to the heterogeneous nature of concrete. The model is validated with experimental data and compared to national codes and macroscopic models, demonstrating its effectiveness in overcoming the gaps in existing models.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Akash Kumar Behera, Mohammad Masiur Rahaman, Debasish Roy
Summary: Ceramics have attractive properties but low fracture toughness is a major drawback. There is interest in improving the mechanical performance of ceramics by tailoring residual stresses. However, there is a lack of computational models that can accurately predict crack paths and quantify the improved fracture toughness.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Bineet Kumar, Sandeep Kumar Dubey, Sonalisa Ray
Summary: This study aims to develop an energy-based theoretical formulation for predicting the evolution of the fracture process zone in concrete under fatigue loading. Experimental results and calibrations indicate that the specimen size and aggregate size affect the fracture behavior and process zone length of concrete.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Zheliang Wang, Hao Sheng, Xinyi Lin, Yifan Rao, Jia Liu, Nanshu Lu
Summary: In this study, an analytical framework is proposed for investigating the behavior of laminated beams with any number of layers under various bending conditions, and the theory is validated through finite element analysis. It was found that the number of layers, applied deformation, layer properties, and layer aspect ratio have an impact on the equivalent flexural rigidity.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Michael Schwaighofer, Markus Konigsberger, Luis Zelaya-Lainez, Markus Lukacevic, Sebastian Serna-Loaiza, Michael Harasek, Florian Zikeli, Anton Friedl, Josef Fussl
Summary: In this study, nanoindentation relaxation tests were re-evaluated on five industrial lignins extracted from different feedstocks. It was found that the viscoelastic properties of all tested lignins were practically identical and independent of the feedstock and the extraction processes.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Tian Han, Dandan Qi, Jia Ma, Chaoyang Sun
Summary: In this study, a generative design method was used to propose new modified lattice structures suitable for tensile and compressive loading conditions. By conducting experimental and finite element analyses, it was confirmed that the derived structures have improved load-bearing capacity and energy absorption compared to the original structures. The effects of shape parameters on mechanical properties were also discussed.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Wenbin Zheng, Jay Airao, Ramin Aghababaei
Summary: Spinodal decomposition of Ti1-xAlxN crystal structure significantly affects their physical properties. This study uses three-dimensional molecular dynamics simulations to investigate the phase transformation mechanism and surface finish during material removal in TiAlN. The simulations reveal that the aluminum content and cutting depth have a significant influence on the phase transformation process through spinodal decomposition.
MECHANICS OF MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Atasi Ghosh
Summary: The micro-mechanism of low cycle fatigue deformation behavior has been summarized and the recent development in the approach of numerical simulation of cyclic stress-strain behavior of polycrystalline metallic materials at multi-scale has been discussed.
MECHANICS OF MATERIALS
(2024)