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近年来,液晶网络材料因为在人工肌肉、软体机器人、微流控制器和4D打印材料等智能软器件领域的应用受到了越来越多的关注。液晶网络材料在化学结构上同时包含聚合物交联网络和液晶基元,在性能上同时具有聚合物的可加工性、化学稳定性和力学特性以及液晶可调的各向异性,因此具有外观易编辑、功能可调、对多种刺激都能响应等优点。利用这些特点,可以将指定的形状或颜色信息精确地写入到材料中,同时在特定外界刺激（光,热,电场,溶剂等）下使信息再次显现,实现信息的存储、加密与读取。本文简要论述了具有可编辑颜色（包括结构色和荧光颜色）和形状记忆的液晶网络材料的信息存储方式,重点介绍了液晶网络材料在伪装、多级信息存储与信息传递等方面的应用研究进展。 相似文献
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3D programmable materials are highly interesting and have a great potential to enable smart robotic devices. Stimuli‐responsive liquid crystal polymer networks (LCNs) offer an attractive platform for the design and fabrication of 3D programmable materials. To date, extensive efforts have been devoted to the design of 3D programmable LCNs by spatially modulating the orientation of liquid crystals. However, the practical application of LCN actuators has been elusive, partly due to tedious orientation technology and monotonous geometry. To resolve this issue, programmable 3D shape changes achieved in LCNs with uniaxial orientation and homogenous composition using a mechanical programming process inspired by the “programming process” of shape‐memory polymers are reported. The mechanical programming process is suitable for LCNs with distinct geometries, for example, the film and fiber, suggesting a promising way for the design of 3D programmable LCN actuators with complex geometries, and deformation profiles (buckle, helix, horn). 相似文献
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Deng Pan Dong Wu Peng-Ju Li Sheng-Yun Ji Xuan Nie Sheng-Ying Fan Guo-Yang Chen Chen-Chu Zhang Chen Xin Bing Xu SuWan Zhu Ze Cai YanLei Hu JiaWen Li JiaRu Chu 《Advanced functional materials》2021,31(14):2009386
Marangoni-effect-driven actuators (MDAs) have the advantages of direct light-to-work conversion and convenient operation, which makes it widely researched in the cutting-edge fields including robots, micromachines, and intelligent systems. However, the MDA relies on the surface tension difference and it only works on the 2D liquid–air interface. Besides, the MDAs are normally pure black due to the light-absorption material limitation. Herein, a transparent light-driven 3D movable actuator (LTMA) and a 3D manipulation strategy are proposed. The LTMA is composed of photothermal nanoparticles-doped temperature-responsive hydrogel, whose surface energy changes as the nanoparticles absorb light energy. The 3D manipulation strategy combines Marangoni effect with photothermal buoyancy flow for realizing complex self-propellant and floating/sinking motions. The LTMA can perform more advanced tasks such as 3D obstacle avoidance and 3D sampling. Benefiting from the porous structure of hydrogel, LTMA can naturally absorb the chemical molecules for remote sampling and automated drug delivery. The light-driven, transparent, three-dimensionally movable, and programmable actuator has promising prospects in the field of micromachines and intelligent systems. 相似文献
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We report a new strategy to achieve triple shape memory properties by using side‐chain liquid crystalline (SCLC) type random terpolymer networks (XL‐ TP‐n), where n is the length of flexible methylene spacer (n = 5, 10, and 15) to link backbone and mesogen. A lower glass transition temperature (Tg = Tlow) and a higher liquid crystalline clearing temperature (Tcl = Thigh) of XL‐TP‐n serve as molecular switches to trigger a shape memory effect (SME). Two different triple shape creation procedures (TSCPs), thermomechanical treatments to obtain temporary shapes prior to the proceeding recovery step, are used to investigate the triple shape memory behavior of XL‐TP‐n. The discrete Tg and Tcl as well as unique microphase‐separated morphologies (backbone‐rich and mesogen‐rich domains) within smectic layers of XL‐TP‐n enables triple shape memory properties. Motional decoupling between backbone‐rich and mesogen‐rich domains is also critical to determine the resulting macroscopic shape memory properties. Our strategy for obtaining triple shape memory properties will pave the way for exploiting a broad range of SCLC polymers to develop a new class of actively moving polymers. 相似文献
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Smart microstructured materials enable functions such as actuation, detection, transportation, and sensing with potential applications ranging from robotics and photonics to biomedical devices. Of the many materials systems, liquid crystal polymer networks (LCN) are fascinating owing to their ability to exhibit reversible macroscopic deformation driven by a molecular order–disorder phase transition. LCN have been increasingly explored for their utility in the design and fabrication of smart actuating devices capable of complex shape changes or motions upon external stimulation of humidity, heat, light, and other stimuli, and recent studies in this field show that their actuation complexity can be enriched and actuation performance enhanced by having some sort of microstructures. Herein, the recent progress in microstructured actuation of LCN materials with substructures in scale ranging from micrometer to millimeter is reported, placing the emphasis on the main approaches to generating a microstructure in LCN, which include patterned LC director fields, patterned chain crosslinking in LCN with uniaxial orientation of mesogens, 3D/4D printing, and replica molding. The potential applications in microstructured 3D actuators and devices as well as functional LCN surfaces are also highlighted, with an outlook on important issues and future trends in smart microstructured LCN materials and actuators. 相似文献
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Ferran Pujol-Vila Pau Güell-Grau Josep Nogués Mar Alvarez Borja Sepúlveda 《Advanced functional materials》2023,33(14):2213109
Soft optomechanical systems have the ability to reversibly respond to optical and mechanical external stimuli by changing their own properties (e.g., shape, size, viscosity, stiffness, color or transmittance). These systems typically combine the optical properties of plasmonic, dielectric or carbon-based nanomaterials with the high elasticity and deformability of soft polymers, thus opening the path for the development of new mechanically tunable optical systems, sensors, and actuators for a wide range of applications. This review focuses on the recent progresses in soft optomechanical systems, which are here classified according to their applications and mechanisms of optomechanical response. The first part summarizes the soft optomechanical systems for mechanical sensing and optical modulation based on the variation of their optical response under external mechanical stimuli, thereby inducing mechanochromic or intensity modulation effects. The second part describes the soft optomechanical systems for the development of light induced mechanical actuators based on different actuation mechanisms, such as photothermal effects and phase transitions, among others. The final section provides a critical analysis of the main limitations of current soft optomechanical systems and the progress that is required for future devices. 相似文献
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Jinquan Liu Liangliang Xu Qixiao Ji Longfei Chang Ying Hu Qingyu Peng Xiaodong He 《Advanced functional materials》2024,34(4):2310955
Phototropism and self-oscillation are both self-regulating intelligent movements of biological organisms. However, realizing these intelligent movements in one same artificial actuation system remains a great challenge. Here, by introducing dynamic light-mechanical interaction, a MXene-based actuator is designed and fabricated that can generate unique self-adaptive light-driven actuation from the equilibrium state of phototropic deformation to self-oscillation. The actuator can autonomously track the incident light, showing a sunflower-like phototropism. Moreover, by simply installing a load on the actuator to induce self-shadowing-enabled negative feedback loop, it can carry the load to continuously oscillate under constant light irradiation, with a frequency of 6.5 Hz, an amplitude of 2.6 mm, and a load-to-weight ratio value of 4.7. The oscillation frequency and amplitude can be further adjusted by the incident light power, actuator length, and weight of the installed load. This oscillator can serve as an intelligent light-powered motor platform. By installing diverse accessories with different functions on the oscillator, it can realize various applications, including information transmission, light-induced power generation, bionic motions, and multi-mode intelligent switches. These results provide a simple and versatile strategy for designing a self-adaptive oscillator driven by light and show the prospect of the oscillator in light-powered engines and smart machinery systems. 相似文献
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Xiaoyun Xu Zhuang Wang Yupei Su Ke Zhang Min Li Qi Zhang Shuai Zhang Yi Zhao Qinfei Ke Hong Hu Robert J. Young Shanshan Zhu Jinlian Hu 《Advanced functional materials》2024,34(33):2401732
Hydration-induced shape-morphing behavior has been discovered in many natural fiber-based materials, yet this smart behavior in regenerated fibers from biopolymers lacks investigation. Here, hierarchically structured silk fibers are developed with anisotropic long-range molecular organization and water-responsive effects resembling natural spider silk. The regenerated silk fibers exhibit the water-triggered shape-memory effect and a water-driven cyclic response. The reversible hydrogen bonds and transformation in the metastable secondary structure from α-helices/random coils to β-sheets are explored as the mechanisms responsible for the water-responsiveness. The silk fibers obtained possess a tensile strength higher than 104 MPa at a fracture strain of ≈100%, showing noticeable toughness. The water-responsive silk fibers exhibit a shape recovery rate of ∼83% and generate a maximum actuation stress of up to 18 MPa during the water-driven cyclic contraction that outperforms most traditional natural textile fibers. The regenerated silk fibers show potential for use in water-driven actuators, artificial muscle, and smart fabrics based on the integration of suitable mechanical properties and water responsiveness. 相似文献
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Eva L. Kirkby Joseph D. Rule Véronique J. Michaud Nancy R. Sottos Scott R. White Jan‐Anders E. Månson 《Advanced functional materials》2008,18(15):2253-2260
We report the first measurements of self‐healing polymers with embedded shape‐memory alloy (SMA) wires. The addition of SMA wires shows improvements of healed peak fracture loads by up to a factor of 1.6, approaching the performance of the virgin material. Moreover, the repairs can be achieved with reduced amounts of healing agent. The improvements in performance are due to two main effects: (i) crack closure, which reduces the total crack volume and increases the crack fill factor for a given amount of healing agent and (ii) heating of the healing agent during polymerization, which increases the degree of cure of the polymerized healing agent. 相似文献
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Hyun Soon Park Yasukazu Murakami Keiichi Yanagisawa Tsuyoshi Matsuda Ryosuke Kainuma Daisuke Shindo Akira Tonomura 《Advanced functional materials》2012,22(16):3434-3437
Peculiar magnetic domain walls produced in Heusler alloys, which have attracted renewed interest due to their potential application to actuators and spintronic devices, are studied here using electron holography. The observations reveal unexpectedly narrow magnetic domain walls, the width of which showed perfect agreement with that of the antiphase boundaries (APB, e.g., only 3 nm). While the results can be explained by the significant depression of ferromagnetism due to the local chemical disorder, the electron phase shift indicates that ferromagnetic correlation still remains in the APB region. 相似文献
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Programmable soft materials exhibiting dynamically reconfigurable, reversible, fast, and latchable shape transformation are key for applications ranging from wearable tactile actuators to deployable soft robots. Multimorph soft actuator sheets with high load‐bearing capacity are reported, capable of bending on multiple axis, made by combining a single dielectric elastomer actuator (DEA) with two layers of shape memory polymers (SMPs) fibers and an array of stretchable heaters. The rigidity of the SMP fibers can be reduced by two orders of magnitude by Joule heating, thus allowing the orientation and location of soft and hard regions to be dynamically defined by addressing the heaters. When the DEA is then actuated, it bends preferentially along the soft axis, enabling the device to morph into multiple distinct configurations. Cooling down the SMPs locks these shape changes into place. A tip deflection angle of over 300° at 5 kV is achieved with a blocking force of over 27 mN. Devices using two antagonistic DEAs are also reported that attain more complex shapes. Multimorphing is demonstrated by gripping objects with different shapes. An analytical model is developed to determine the design parameters that offers the best trade‐off between large actuation and high holding forces. 相似文献
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Robert Zarnetta Ryota Takahashi Marcus L. Young Alan Savan Yasubumi Furuya Sigurd Thienhaus Burkhard Maaß Mustafa Rahim Jan Frenzel Hayo Brunken Yong S. Chu Vijay Srivastava Richard D. James Ichiro Takeuchi Gunther Eggeler Alfred Ludwig 《Advanced functional materials》2010,20(12):1917-1923
Improving the functional stability of shape memory alloys (SMAs), which undergo a reversible martensitic transformation, is critical for their applications and remains a central research theme driving advances in shape memory technology. By using a thin‐film composition‐spread technique and high‐throughput characterization methods, the lattice parameters of quaternary Ti–Ni–Cu–Pd SMAs and the thermal hysteresis are tailored. Novel alloys with near‐zero thermal hysteresis, as predicted by the geometric non‐linear theory of martensite, are identified. The thin‐film results are successfully transferred to bulk materials and near‐zero thermal hysteresis is observed for the phase transformation in bulk alloys using the temperature‐dependent alternating current potential drop method. A universal behavior of hysteresis versus the middle eigenvalue of the transformation stretch matrix is observed for different alloy systems. Furthermore, significantly improved functional stability, investigated by thermal cycling using differential scanning calorimetry, is found for the quaternary bulk alloy Ti50.2Ni34.4Cu12.3Pd3.1. 相似文献
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In this paper, the fabrication and characterization of triple‐shape polymeric composites (TSPCs) that, unlike traditional shape memory polymers (SMPs), are capable of fixing two temporary shapes and recovering sequentially from the first temporary shape (shape 1) to the second temporary shape (shape 2), and eventually to the permanent shape (shape 3) upon heating, are reported. This is technically achieved by incorporating non‐woven thermoplastic fibers (average diameter ～760 nm) of a low‐Tm semicrystalline polymer into a Tg‐based SMP matrix. The resulting composites display two well‐separated transitions, one from the glass transition of the matrix and the other from the melting of the fibers, which are subsequently used for the fixing/recovery of two temporary shapes. Three thermomechanical programming processes with different shape fixing protocols are proposed and explored. The intrinsic versatility of this composite approach enables an unprecedented large degree of design flexibility for functional triple‐shape polymers and systems. 相似文献
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Photoresponsive actuators are built by introducing oligo(ethylene glycol) (OEG)‐modified W18O49 nanowires into cross‐linked polyethylene glycol diacrylate (cPEGDA) polymer matrices. Due to the good compatibility, OEG‐W18O49 NWs disperse well and increase the crystallinity of cPEGDA matrices even in high loading concentrations (4.0 wt%). The cPEGDA/W18O49 nanocomposites show efficient photothermal transition and rapid shape memory behaviors. They can raise the local temperature to 160 °C in only 8.5 s and recover the initial shape within 10 s. Making use of the broad and strong absorption property of W18O49, the cPEGDA/W18O49 NW actuators respond to both ultraviolet and near‐infrared light and make contraction and bending motions. Furthermore, by utilizing oriented chain segments of the crystalline polymer and vector sum of shape recovery forces, the cPEGDA/W18O49 NW hybrid actuators exhibit stable helical deformation (right‐handed and left‐handed). 相似文献
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Laurens T. de Haan Vianney Gimenez‐Pinto Andrew Konya Thanh‐Son Nguyen Julien M. N. Verjans Carlos Sánchez‐Somolinos Jonathan V. Selinger Robin L. B. Selinger Dirk J. Broer Albertus P. H. J. Schenning 《Advanced functional materials》2014,24(9):1251-1258
This work describes the fabrication, characterization, and modelling of liquid crystalline polymer network films with a multiple patterned 3D nematic director profile, a stimuli‐responsive material that exhibits complex mechanical actuation under change of temperature or pH. These films have a discrete alternating striped or checkerboard director profile in the plane, and a 90‐degree twist through the depth of the film. When actuated via heating, the striped films deform into accordion‐like folds, while the film patterned with a checkerboard microstructure buckles out‐of‐plane. Furthermore, striped films are fabricated so that they also deform into an accordion shaped fold, by a change of pH in an aqueous environment. Three‐dimensional finite element simulations and elasticity analysis provide insight into the dependence of shape evolution on director microstructure and the sample's aspect ratio. 相似文献
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描述了图形液晶模块的汉字显示方法,以8051单片机为基础,介绍了液晶模块与单片机的典型接口电路;叙述了单片机系统中3种汉字字模存储和提取的方法:一是字模存放在程序存储器中;二是通过外扩的E2PROM存储汉字字模数据,将其作为外部数据存储器进行寻址;三是使用外扩的E2PROM存储整个汉字库,通过汉字区位码寻址汉字库进行字模提取。 相似文献
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Hafeez Ur Rehman Yujie Chen Mikael S. Hedenqvist Hua Li Wenchao Xue Yunlong Guo Yiping Guo Huanan Duan Hezhou Liu 《Advanced functional materials》2018,28(7)
New polyurethane‐based polycaprolactone copolymer networks, with shape recovery properties, are presented here. Once deformed at ambient temperature, they show 100% shape fixation until heated above the melting point, where they recover the initial shape within 22 s. In contrast to current shape memory materials, the new materials do not require deformation at elevated temperature. The stable polymer structure of polyurethane yields a copolymer network that has strength of 10 MPa with an elongation at break of 35%. The copolymer networks are self‐healing at a slightly elevated temperature (70 °C) without any external force, which is required for existing self‐healing materials. This allows for the new materials to have a long life of repeated healing cycles. The presented copolymers show features that are promising for applications as temperature sensors and activating elements. 相似文献