共查询到20条相似文献,搜索用时 62 毫秒
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Chong Luo Che‐Ning Yeh Jesus M. Lopez Baltazar Chao‐Lin Tsai Jiaxing Huang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(15)
Properly cut sheets can be converted into complex 3D structures by three basic operations including folding, bending, and pasting to render new functions. Folding and bending are extensively employed in crumpling, origami, and pop‐up fabrications for 3D structures. Pasting joins different parts of a material together, and can create new geometries that are fundamentally unattainable by folding and bending. However, it has been much less explored, likely due to limited choice of weldable thin film materials and residue‐free glues. Here it is shown that graphene oxide (GO) paper is one such suitable material. Stacked GO sheets can be readily loosened up and even redispersed in water, which upon drying, restack to form solid structures. Therefore, water can be utilized to heal local damage, glue separated pieces, and release internal stress in bent GO papers to fix their shapes. Complex and dynamic 3D GO architectures can thus be fabricated by a cut‐and‐paste approach, which is also applicable to GO‐based hybrid with carbon nanotubes or clay sheets. 相似文献
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Liquid‐Crystalline Elastomers: High‐Resolution 3D Direct Laser Writing for Liquid‐Crystalline Elastomer Microstructures (Adv. Mater. 15/2014) 下载免费PDF全文
Hao Zeng Daniele Martella Piotr Wasylczyk Giacomo Cerretti Jean‐Christophe Gomez Lavocat Chih‐Hua Ho Camilla Parmeggiani Diederik Sybolt Wiersma 《Advanced materials (Deerfield Beach, Fla.)》2014,26(15):2285-2285
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Owies M. Wani Rob Verpaalen Hao Zeng Arri Priimagi Albert P. H. J. Schenning 《Advanced materials (Deerfield Beach, Fla.)》2019,31(2)
Beyond their colorful appearances and versatile geometries, flowers can self‐shape‐morph by adapting to environmental changes. Such responses are often regulated by a delicate interplay between different stimuli such as temperature, light, and humidity, giving rise to the beauty and complexity of the plant kingdom. Nature inspires scientists to realize artificial systems that mimic their natural counterparts in function, flexibility, and adaptation. Yet, many of the artificial systems demonstrated to date fail to mimic the adaptive functions, due to the lack of multi‐responsivity and sophisticated control over deformation directionality. Herein, a new class of liquid‐crystal‐network (LCN) photoactuators whose response is controlled by delicate interplay between light and humidity is presented. Using a novel deformation mechanism in LCNs, humidity‐gated photoactuation, an artificial nocturnal flower is devised that is closed under daylight conditions when the humidity level is low and/or the light level is high, while it opens in the dark when the humidity level is high. The humidity‐gated photoactuators can be fueled with lower light intensities than conventional photothermal LCN actuators. This, combined with facile control over the speed, geometry, and directionality of movements, renders the “nocturnal actuator” promising for smart and adaptive bioinspired microrobotics. 相似文献
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Matthew K. McBride Matthew Hendrikx Danqing Liu Brady T. Worrell Dirk J. Broer Christopher N. Bowman 《Advanced materials (Deerfield Beach, Fla.)》2017,29(17)
Photoactivated reversible addition fragmentation chain transfer (RAFT)‐based dynamic covalent chemistry is incorporated into liquid crystalline networks (LCNs) to facilitate spatiotemporal control of alignment, domain structure, and birefringence. The RAFT‐based bond exchange process, which leads to stress relaxation, is used in a variety of conditions, to enable the LCN to achieve a near‐equilibrium structure and orientation upon irradiation. Once formed, and in the absence of subsequent triggering of the RAFT process, the (dis)order in the LCN and its associated birefringence are evidenced at all temperatures. Using this approach, the birefringence, including the formation of spatially patterned birefringent elements and surface‐active topographical features, is selectively tuned by adjusting the light dose, temperature, and cross‐linking density. 相似文献
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Liquid‐Crystalline Dynamic Networks Doped with Gold Nanorods Showing Enhanced Photocontrol of Actuation 下载免费PDF全文
Xili Lu Hu Zhang Guoxia Fei Bing Yu Xia Tong Hesheng Xia Yue Zhao 《Advanced materials (Deerfield Beach, Fla.)》2018,30(14)
A near‐infrared‐light (NIR)‐ and UV‐light‐responsive polymer nanocomposite is synthesized by doping polymer‐grafted gold nanorods into azobenzene liquid‐crystalline dynamic networks (AuNR‐ALCNs). The effects of the two different photoresponsive mechanisms, i.e., the photochemical reaction of azobenzene and the photothermal effect from the surface plasmon resonance of the AuNRs, are investigated by monitoring both the NIR‐ and UV‐light‐induced contraction forces of the oriented AuNR‐ALCNs. By taking advantage of the material's easy processability, bilayer‐structured actuators can be fabricated to display photocontrollable bending/unbending directions, as well as localized actuations through programmed alignment of azobenzene mesogens in selected regions. Versatile and complex motions enabled by the enhanced photocontrol of actuation are demonstrated, including plastic “athletes” that can execute light‐controlled push‐ups or sit‐ups, and a light‐driven caterpillar‐inspired walker that can crawl forward on a ratcheted substrate at a speed of about 13 mm min‐1. Moreover, the photomechanical effects arising from the two types of light‐triggered molecular motion, i.e., the trans–cis photoisomerization and a liquid‐crystalline–isotropic phase transition of the azobenzene mesogens, are added up to design a polymer “crane” that is capable of performing light‐controlled, robot‐like, concerted macroscopic motions including grasping, lifting up, lowering down, and releasing an object. 相似文献
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Toward Activity Origin of Electrocatalytic Hydrogen Evolution Reaction on Carbon‐Rich Crystalline Coordination Polymers 下载免费PDF全文
Lihuan Wang Diana C. Tranca Jian Zhang Yanpeng Qi Stavroula Sfaelou Tao Zhang Renhao Dong Xiaodong Zhuang Zhikun Zheng Gotthard Seifert 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(37)
The fundamental understanding of electrocatalytic active sites for hydrogen evolution reaction (HER) is significantly important for the development of metal complex involved carbon electrocatalysts with low kinetic barrier. Here, the MSx Ny (M = Fe, Co, and Ni, x /y are 2/2, 0/4, and 4/0, respectively) active centers are immobilized into ladder‐type, highly crystalline coordination polymers as model carbon‐rich electrocatalysts for H2 generation in acid solution. The electrocatalytic HER tests reveal that the coordination of metal, sulfur, and nitrogen synergistically facilitates the hydrogen ad‐/desorption on MSx Ny catalysts, leading to enhanced HER kinetics. Toward the activity origin of MS2N2, the experimental and theoretical results disclose that the metal atoms are preferentially protonated and then the production of H2 is favored on the M? N active sites after a heterocoupling step involving a N‐bound proton and a metal‐bound hydride. Moreover, the tuning of the metal centers in MS2N2 leads to the HER performance in the order of FeS2N2 > CoS2N2 > NiS2N2. Thus, the understanding of the catalytic active sites provides strategies for the enhancement of the electrocatalytic activity by tailoring the ligands and metal centers to the desired function. 相似文献
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Xinlei Pang Jiu‐an Lv Chongyu Zhu Lang Qin Yanlei Yu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(52)
Photodeformable liquid crystal polymers (LCPs) that adapt their shapes in response to light have aroused a dramatic growth of interest in the past decades, since light as a stimulus enables the remote control and diverse deformations of materials. This review focuses on the growing research on photodeformable LCPs, including their basic actuation mechanisms, the various deformation modes, the newly designed molecular structures, and the improvement of processing techniques. Special attention is devoted to the novel molecular structures of LCPs, which allow for easy processing and alignment. The soft actuators with various deformation modes such as bending, twisting, and rolling in response to light are also covered with the emphasis on their photo‐induced bionic functions. Potential applications in energy harvesting, self‐cleaning surfaces, sensors, and photo‐controlled microfluidics are further illustrated. The existing challenges and future directions are discussed at the end of this review. 相似文献
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Ankit Agarwal Sumyra Sidiq Shilpa Setia Emre Bukusoglu Juan J. de Pablo Santanu Kumar Pal Nicholas L. Abbott 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(16):2785-2792
This paper advances the design of stimuli‐responsive materials based on colloidal particles dispersed in liquid crystals (LCs). Specifically, thin films of colloid‐in‐liquid crystal (CLC) gels undergo easily visualized ordering transitions in response to reversible and irreversible (enzymatic) biomolecular interactions occurring at the aqueous interfaces of the gels. In particular, LC ordering transitions can propagate across the entire thickness of the gels. However, confinement of the LC to small domains with lateral sizes of ~10 μm does change the nature of the anchoring transitions, as compared to films of pure LC, due to the effects of confinement on the elastic energy stored in the LC. The effects of confinement are also observed to cause the response of individual domains of the LC within the CLC gel to vary significantly from one to another, indicating that manipulation of LC domain size and shape can provide the basis of a general and facile method to tune the response of these LC‐based physical gels to interfacial phenomena. Overall, the results presented in this paper establish that CLC gels offer a promising approach to the preparation of self‐supporting, LC‐based stimuli‐responsive materials. 相似文献
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3D printing or fabrication pursues the essential surface behavior manipulation of droplets or a liquid for rapidly and precisely constructing 3D multimaterial architectures. Further development of 3D fabrication desires a self‐shaping strategy that can heterogeneously integrate functional materials with disparate electrical or optical properties. Here, a 3D liquid self‐shaping strategy is reported for rapidly patterning materials over a series of compositions and accurately achieving micro‐ and nanoscale structures. The predesigned template selectively pins the droplet, and the surface energy minimization drives the self‐shaping processing. The as‐prepared 3D circuits assembled by silver nanoparticles carry a current of 208–448 µA at 0.01 V impressed voltage, while the 3D architectures achieved by two different quantum dots show noninterfering optical properties with feature resolution below 3 µm. This strategy can facilely fabricate micro‐nanogeometric patterns without a modeling program, which will be of great significance for the development of 3D functional devices. 相似文献
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R. Houbertz L. Frhlich M. Popall U. Streppel P. Dannberg A. Bruer J. Serbin B.N. Chichkov 《Advanced Engineering Materials》2003,5(8):551-555
Sol‐gel synthesis allows inorganic–organic hybrid polymer materials (ORMOCER®s) to be produced, which can be functionalized to tailor their physical and chemical properties such as refractive index or optical loss. A particular material system is discussed here, which is synthesized without addition of water and is applied in optical communications. As examples for 2D and 2.5D technology, planar waveguides, stacked waveguides, and microlenses are shown. Using two‐photon polymerization initiated by femtosecond laser pulses, arbitrary 3D structures can be made in the submicrometer range. In particular, 3D photonic crystal structures are described and discussed. 相似文献