共查询到20条相似文献，搜索用时 15 毫秒
1.
Lidong Zhang Stanislav Chizhik Yunze Wen Panče Naumov 《Advanced functional materials》2016,26(7):1040-1053
The capability of cellulose microfibrils to elicit directionality by anisotropically restricting the deformation of amorphous biogenic matrices is central to the motility of many plants as motoric and shape‐restoring elements. Herein, an approach is described to control directionality of artificial composite actuators that mimic the hygroinduced motion of composite plant tissues such as the opening of seed pods, winding of plant tendrils, and burial of seed awns. The actuators are designed as bilayer structures where single or double networks of buried parallel glass fibers reinforce the composite. By anisotropically restricting the expansion along certain directions they also effectively direct the mechanical reconfiguration, thereby determining the mechanical effect. A mathematical model is developed to quantify the kinematic response of fiber‐reinforced actuators. Within a broader context, the results of this study provide means for control over mechanical deformation of artificial dynamic elements that mimic the oriented fibrous architectures in biogenic motoric elements. 相似文献
2.
液晶高分子是同时具有液晶各向异性和高分子力学特性的功能高分子。在液晶高分子中引入具有光化学异构化或者光热响应的结构单元,可以使其在光或者热刺激下发生相转变,引发宏观形状变化。通过一步或两步的取向方法可以对液晶高分子中液晶基元的取向方向进行调控,实现材料的变形编程。液晶高分子形态上的变化在仿生软机器人、微流控、柔性执行器、结构色和防伪等领域有潜在的应用价值。本文介绍了液晶高分子主要的取向技术和开发出的基于形状变化的器件功能,并展望了液晶高分子形变材料在高新科技领域的应用前景。 相似文献
3.
Roland Fuhrer Christoph M. Schumacher Martin Zeltner Wendelin J. Stark 《Advanced functional materials》2013,23(31):3845-3849
The combination of force and flexibility enables controlled and soft movements. In sharp contrast, presently used machines are solid and mostly based on stiff driveshafts or cog wheels. Magnetic elastomers are realized through dispersion of small particles in polymer matrices and have attracted significant interest as soft actuators for controlled movement or conveying and are particularly attractive candidates for magnetic pump applications. At present, low magnetic particle loading and thus limited actuator strength have restricted the application of such materials. Here, the direct incorporation of metal microparticles into a very soft and flexible silicone and its application as an ultra‐flexible, yet strong magnetic tube, is described. Because metals have a far higher saturation magnetization and higher density than oxides, the resulting increased force/volume ratio afforded significantly stronger magnetic actuators with high mechanical stability, flexibility, and shape memory. Elliptical inner diameter shape of the tubing allowed a very efficient contraction of the tube by applying an external magnetic field. The combination of magnetic silicone tubes and a magnetic field generating device results in a magnetic peristaltic pump. 相似文献
4.
Manipulating the shape of preformed living tissues can present a novel fabrication route toward complex biological architectures. However, external manipulation of tissues can be challenging to implement robustly at multiple length scales and with high degrees of freedom, particularly in soft fibrous tissue constructs. Here, a versatile platform is developed to drive soft tissue morphodynamics using embeddable shape memory actuators that generate multiscale, repetitive, and highly customized tissue deformation on demand. To achieve this, a thermally isolating coating technique is designed and developed for programmable shape memory wires, which protects surrounding biological materials from cytotoxic heating effects during wire actuation. The coated tissue actuators (CTAs) can then be embedded in engineered tissues and activated to produce both large‐ and small‐scale tissue deformations in a highly customized and reproducible manner. Using this strategy, tissues can be forced to adopt specified shapes, with precise control over cell elongation and orientation within an encapsulating matrix. Furthermore, the system can produce predictable, highly localized, and customizable strains within fibrous matrices, capable of elongating cells and biasing their orientation within degrees of a desired direction. This strategy may hence have broad applicability in both applied tissue biofabrication and for fundamental studies of cell–matrix interactions. 相似文献
5.
Seung Hui Han Seok-In Lim Ki-Hyun Ryu Jahyeon Koo Dong-Gue Kang Kwang-Un Jeong Seung-Yeol Jeon Dae-Yoon Kim 《Advanced functional materials》2023,33(3):2210680
Examples of anisotropic movement paired with helical geometry abound in the animal and plant kingdoms are used for a variety of reasons, such as diverse social signaling directed at conspecifics or camouflage to avoid predation. Inspired by these natural phenomena, a smart sensor is developed with a chiroptical 3D actuator that can fold, bend, and twist in response to external stimuli, reflecting light of specific wavelengths, and possessing circular polarization properties. Chirophotonic crystal actuators are constructed with an asymmetric Janus structure and are fabricated by self-assembly, screen printing, and in situ photopolymerization. The optically active layer consists of cholesteric liquid crystal polymer, and the mechanically active layer is composed of a polymeric gel thin film. The programmed in-planar and out-of-planar asymmetric Janus structures control the directionality of various shapes morphing from 2D to 3D. Finite element simulations allow to predict the shape changes associated with these chirophotonic crystal actuators: flower blooming, tendril climbing, eagle hunting, ant lifting, and inchworm moving motions. By utilizing the chirophotonic crystal actuator, a reusable and portable methanol-laced water identifier is developed. 相似文献
6.
Wei Wang Chenzhe Li Hugo Rodrigue Fengpei Yuan Min‐Woo Han Maenghyo Cho Sung‐Hoon Ahn 《Advanced functional materials》2017,27(7)
The beam steering mechanism has been a key element for various applications ranging from sensing and imaging to solar tracking systems. However, conventional beam steering systems are bulky and complex and present significant challenges for scaling up. This work introduces the use of soft deployable reflectors combining a soft deployable structure with simple kirigami/origami reflective films. This structure can be used as a macroscale beam steering mechanism that is both simple and compact. This work first develops a soft deployable structure that is easily scalable by patterning of soft linear actuators. This soft deployable structure is capable of increasing its height several folds by expanding in a continuous and controllable manner, which can be used as a frame to deform the linearly stretchable kirigami/origami structures integrated into the structure. Experiments on the reflective capability of the reflectors are conducted and show a good fit to the modeling results. The proposed principles for deployment and for beam steering can be used to realize novel active beam steering devices, highlighting the use of soft robotic principles to produce scalable morphing structures. 相似文献
7.
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
8.
Sam Peerlinck Edoardo Milana Elias De Smet Michael De Volder Dominiek Reynaerts Benjamin Gorissen 《Advanced functional materials》2023,33(32):2300856
Human ingenuity has found a multitude of ways to manipulate fluids across different applications. However, the fundamentals of fluid propulsion change when moving from the macro- to the microscale. Viscous forces dominate inertial forces rendering successful methods at the macroscale ineffective for microscale fluid propulsion. Nature however has found a solution; microscopic active organelles protruding from cells that feature intricate beating patterns: cilia. Cilia succeed in propelling fluids at small dimensions; hence they have served as a source of inspiration for microfluidic applications. Mimicking biological cilia however remains challenging due to their small size and the required kinematic complexity. Recent advances have pushed artificial cilia technology forward, yet discrepancies with natural cilia still exists. This study identifies this gap by analyzing artificial cilia technology and benchmarking them to natural cilia, to pinpoint the remaining design and manufacturing challenges that lay at the basis of the disparity with nature. 相似文献
9.
Jianliang Xiao Haitao Liu Shan Wang Shuqi Ma Lei Zhang Yizhou Qi 《Advanced functional materials》2024,34(32):2316301
Developing stimulus-responsive materials (SRMs) with reversible, large, and reprogrammable multi-responsiveness is crucial for soft actuators and intelligent devices, which remains challenging. In this study, regenerated silk fibroin with hierarchical structure is utilized to specially design a reprogrammable multi-stimuli-responsive protein film and versatile soft actuators. The freestanding fibroin films exhibit notable thermal contraction (−1383 ppm K−1) and humidity-responsiveness that can be repeatedly regulated by easy post-treatment with Ca2+ as desired. The actuating and regulating mechanisms involve reversible conformational change that is magnified into macroscopic deformations by hierarchical structure, and the roles of material structure and ambient conditions in determining actuating performances are analyzed based on thermodynamics. Driven by humidity gradient, the fibroin film demonstrates spontaneous flipping locomotion, self-oscillation with tunable frequencies, bio-butterfly wing flapping, and transformation from 2D to 3D structure. Moreover, reprogrammable deformations at specific regions are achieved in multi-stimuli-driven PET/fibroin film actuators owing to the straightforward Ca2+-content-based tunability of the responsiveness. The fibroin-based actuators can be used as artificial muscles to drive the high-frequency wing-flapping of a bio-dragonfly and soft gripper to grasp, lift, and transfer objects. The simple yet effective strategy presented herein provides valuable inspiration for designing advanced SRMs and soft actuators with reprogrammable multi-responsiveness. 相似文献
10.
Ren Zheng Lingling Ma Wei Feng Jintao Pan Zeyu Wang Zhaoxian Chen Yiheng Zhang Chaoyi Li Peng Chen Hari Krishna Bisoyi Bingxiang Li Quan Li Yanqing Lu 《Advanced functional materials》2023,33(38):2301142
Advances in biomimicry have led to the rise of advanced robotics, posing promising revolutions across a variety of fields. Programmable self-sustained actuation in nature, such as human's heart beating, bird's wingbeats, and penguin's waddling, are intriguing and inspiring but challenging for device innovation, which hinders the emergence of autonomous self-feedback applications, especially in optics and photonics. Herein, the design, fabrication, and operation of crosslinked liquid crystal actuators are described that combine the programming of microstructures and the engineering of macroscopic shape morphing for active optics and photonics. The actuators consist of twisted nematic liquid crystal molecules with both elastic and optical anisotropies, resulting in large bending deformations in response to heat. Programmable bending motions and self-sustained waddling oscillations are demonstrated, further contributing to the achievements of dynamic 2D beam steering and self-sustained light field modulation. It is envisioned that these actuators with self-sustained performances without requiring turning the stimulus on-off will find applications in autonomous active optical systems, photonic applications, as well as self-governing robotics with the core feature of thermo-mechanical-optical transduction. 相似文献
11.
Yan He Kangren Kong Zhengxi Guo Weifeng Fang Zaiqiang Ma Haihua Pan Ruikang Tang Zhaoming Liu 《Advanced functional materials》2021,31(26):2101291
Sensitivity and multi-directional motivation are major two factors for developing optimized humidity-response materials, which are promising for sensing, energy production, etc. Organic functional groups are commonly used as the water sensitive units through hydrogen bond interactions with water molecules in actuators. The multi-coordination ability of inorganic ions implies that the inorganic ionic compounds are potentially superior water sensitive units. However, the particle forms of inorganic ionic compounds produced by classical nucleation limit the number of exposed ions to interact with water. Recent progress on the inorganic ionic oligomers has broken through the limitation of classical nucleation, and realized the molecular-scaled incorporation of inorganic ionic compounds into an organic matrix. Here, the incorporation of hydrophilic calcium carbonate ionic oligomers into hydrophobic poly(vinylidene fluoride) (PVDF) is demonstrated. The ultra-small calcium carbonate oligomers within a PVDF film endow it with an ultra-sensitive, reversible, and bidirectional response. The motivation ability is superior to other bidirectional humidity-actuators at present, which realizes self-motivation on an ice surface, converting the chemical potential energy of the humidity gradient from ice to kinetic energy. 相似文献
12.
Christian Ohm Eva‐Kristina Fleischmann Isabelle Kraus Christophe Serra Rudolf Zentel 《Advanced functional materials》2010,20(24):4314-4322
In this article new results on the preparation of monodisperse particles from a liquid crystalline elastomer in a microfluidic setup are presnted. For this, droplets from a liquid crystalline monomer are prepared in a microfluidic device and polymerized while they are flowing inside a microtube. The particles obtained by this method possess an internal orientation, which gives them actuating properties. When they are heated into the isotropic phase of the liquid crystalline material they show a reversible change in shape whereby they change their length in one direction by almost 100%. It is shown how the variation of experimental parameters during their synthesis impacts the properties of these micro‐actuators. Influence over their primal shape, the strength of their shape changing properties, their size, and their mechanical properties is demontrated. From the systematic variation of experimental parameters a deep understanding of the complex processes taking place in a flowing droplet of a liquid crystalline material is obtainted. Additionally NMR analysis and swelling experiments on these actuating materials are provided. 相似文献
13.
Christian Ohm Eva‐Kristina Fleischmann Isabelle Kraus Christophe Serra Rudolf Zentel 《Advanced functional materials》2010,20(24):4210-4210
In this article new results on the preparation of monodisperse particles from a liquid crystalline elastomer in a microfluidic setup are presnted. For this, droplets from a liquid crystalline monomer are prepared in a microfluidic device and polymerized while they are flowing inside a microtube. The particles obtained by this method possess an internal orientation, which gives them actuating properties. When they are heated into the isotropic phase of the liquid crystalline material they show a reversible change in shape whereby they change their length in one direction by almost 100%. It is shown how the variation of experimental parameters during their synthesis impacts the properties of these micro‐actuators. Influence over their primal shape, the strength of their shape changing properties, their size, and their mechanical properties is demontrated. From the systematic variation of experimental parameters a deep understanding of the complex processes taking place in a flowing droplet of a liquid crystalline material is obtainted. Additionally NMR analysis and swelling experiments on these actuating materials are provided. 相似文献
14.
Jang Hwan Kim Hyeong Min Jin Geon Gug Yang Kyu Hyo Han Taeyeong Yun Jin Yong Shin Seong‐Jun Jeong Sang Ouk Kim 《Advanced functional materials》2020,30(2)
Nanoscale fabrication of smart materials relying on the molecular self‐assembly of block copolymers (BCPs) has been recognized as a valuable platform for various next‐generation functional structures. In this Progress Report, the recent advances in the BCP self‐assembly process, which has paved the way for viable applications of emerging nanotechnologies, are highlighted. Effective light‐induced self‐assembly based on photothermal annealing of high‐χ BCPs and conformal 3D surface nanopatterning exploiting chemically modified graphene flexible substrates are reviewed as the typical instances of advanced BCP‐based nanofabrication methodologies. Additionally, relevant potential application fields are suggested, namely, graphene nanoribbon field effect transistors, highly tunable refractive index metasurfaces for visible light, high‐sensitivity surface‐enhanced Raman spectroscopy, 2D transition metal dichalcogenide nanopatterning, sequential infiltration synthesis, and organic photovoltaics. Finally, the future research direction as well as innovative applications of these smart nanostructured materials is proposed. 相似文献
15.
S. Macrae Montgomery Shuai Wu Xiao Kuang Connor D. Armstrong Cole Zemelka Qiji Ze Rundong Zhang Ruike Zhao H. Jerry Qi 《Advanced functional materials》2021,31(3):2005319
Mechanical metamaterials are architected manmade materials that allow for unique behaviors not observed in nature, making them promising candidates for a wide range of applications. Existing metamaterials lack tunability as their properties can only be changed to a limited extent after the fabrication. Herein, a new magneto-mechanical metamaterial is presented that allows great tunability through a novel concept of deformation mode branching. The architecture of this new metamaterial employs an asymmetric joint design using hard-magnetic soft active materials that permits two distinct actuation modes (bending and folding) under opposite-direction magnetic fields. The subsequent application of mechanical compression leads to the deformation mode branching where the metamaterial architecture transforms into two distinctly different shapes, which exhibit very different deformations and enable great tunability in properties such as mechanical stiffness and acoustic bandgaps. Furthermore, this metamaterial design can be incorporated with magnetic shape memory polymers with global stiffness tunability, which also allows for the global shift of the acoustic behaviors. The combination of magnetic and mechanical actuations, as well as shape memory effects, impart wide tunable properties to a new paradigm of metamaterials. 相似文献
16.
Magnetoactive soft materials, typically composed of magnetic particles dispersed in a soft polymer matrix, are finding many applications in soft robotics due to their reversible and remote shape transformations under magnetic fields. To achieve complex shape transformations, anisotropic, and heterogeneous magnetization profiles must be programmed in the material. However, once programmed and assembled, magnetic soft actuators cannot be easily reconfigured, repurposed, or repaired, which limits their application, their durability, and versatility in their design. Here, magnetoactive soft composites are developed from squid-derived biopolymers and NdFeB microparticles with tunable ferromagnetic and thermomechanical properties. By leveraging reversible crosslinking nanostructures in the biopolymer matrix, a healing-assisted assembly process is developed that allows for on-demand reconfiguration and magnetic reprogramming of magnetoactive composites. This concept in multi-material modular actuators is demonstrated with programmable deformation modes, self-healing properties to recover their function after mechanical damage, and shape-memory behavior to lock in their preferred configuration and un-actuated catch states. These dynamic magnetic soft composites can enable the modular design and assembly of new types of magnetic actuators, not only eliminating device vulnerabilities through healing and repair but also by providing adaptive mechanisms to reconfigure their function on demand. 相似文献
17.
18.
Dazhao Wang Shiyu Zhang Jingfei Chen Degui Tu Shichao Lv Zheng Wei Bin Tang Zhijia Sun Jianrong Qiu Shifeng Zhou 《Advanced functional materials》2024,34(36):2401992
The sensitive and rapid detection of thermal neutrons holds significant importance in various fields such as energy utilization, medical treatment, and national defense. However, the available thermal neutron scintillator is difficult to reach this target, mainly limited by the optical and scintillating performance. Herein, the in situ crystallization strategy of glass to construct scintillation glass composites for efficient thermal neutron detection is proposed. The congruent crystallization of the hybridized alkali earth silicate glass system may not only achieve high crystallinity, but also will keep the refractive indexing matching between the precipitated crystal and precursor glass phases. The prepared glass composites feature high luminescence efficiency, optical transmission and excellent neutron response properties. These factors collectively contribute to the robust neutron scintillation performance with a light output of ≈36 000 photons/neutron, which represents the highest value among glass-based scintillators. Moreover, the composite configuration brings about the additional function of thermal neutron and γ-ray discrimination. By using this composite scintillator, the neutron detector is constructed and demonstrates its application for detecting thermal neutron and distinguishing it from γ-ray in an online way. The studies prove that glass composites with high crystallinity are expected to be promising candidates for a new generation of multifunctional neutron detectors. 相似文献
19.
Light‐Controlled Actuation,Transduction, and Modulation of Magnetic Strength in Polymer Nanocomposites 
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下载免费PDF全文 Johannes M. Haberl Antoni Sánchez‐Ferrer Ann M. Hirt Raffaele Mezzenga 《Advanced functional materials》2014,24(21):3179-3186
Remotely controlled actuation with wireless sensorial feed‐back is desirable for smart materials to obtain fully computer‐controlled actuators. A light‐controllable polymeric material is presented, in which exposure to light couples with a change in magnetic properties, allowing light signal conversion into non‐volatile magnetic memory. The same material can serve, additionally, both as actuator and transducer, and allows the monitoring of its two‐way elastic shape‐changes by magnetic read‐out. In order to tune the macroscopic magnetic properties of the material, both the reorientation of i) shape anisotropic ferrimagnetic nano‐spindles and ii) a mechanically and magnetically coupled liquid‐crystalline elastomer (LCE) matrix are controlled. These materials are envisioned to have great potential for the development of innovative functional objects, for example, computer‐controlled smart clothing, sensors, signal encoding, micro‐valves, and robotic devices. 相似文献
20.
The ability to dynamically reconfigure superlattices in response to external stimuli is an intriguing prospect for programmable DNA‐guided nanoparticle (NP) assemblies, which promises the realization of “smart” materials with dynamically adjustable interparticle spacing and real‐time tunable properties. Existing in situ probes of reconfiguration processes have been limited mostly to reciprocal space methods, which can follow larger ordered ensembles but do not provide access to real‐space pathways and dynamics. Here, in situ atomic force microscopy is used to investigate DNA‐linked NP assemblies and their response to external stimuli, specifically the contraction and expansion of on‐surface self‐assembled monolayer superlattices upon reversible DNA condensation induced by ethanol. In situ microscopy allows observation and quantification of key processes in solution, e.g., lattice parameter changes, defects, and monomer displacements in small groups of NPs. The analysis of imaging data uncovers important boundary conditions due to DNA bonding of NP superlattices to a substrate. Tension in the NP–substrate DNA bonds, which can elastically extend, break, and re‐form during contraction/expansion cycles, counteracts the changes in lattice parameter and causes hysteresis in the response of the system. The results provide insight into the behavior of supported DNA‐linked NP superlattices and establish a foundation for designing and probing tunable nanocrystal‐based materials in solution. 相似文献