Bioinspired MXene-Based Soft Actuators Exhibiting Angle-Independent Structural Color

In nature,many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots.However,it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying bird.Herein,we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO_(2) nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the interstices.The resulting soft actuators are found to exhibit brilliant,angle-independent structural color,as well as ultrafast actuation and recovery speeds(a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s,and a recovery time of~0.24 s)in response to acetone vapor.As proof-of-concept illustrations,structural colored soft actuators are applied to demonstrate a blue gripper-like bird’s claw that can capture the target,artificial green tendrils that can twine around tree branches,and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone vapor.The strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines.

Dielectric properties of ternary composites of triblock polymer surfactant, liquid crystal and organic solvent

Dielectric spectroscopy,at room temperature(20℃),is used to study the dielectric response of ternary mixtures of commercial nematic liquid crystal mixtures E7 and E33,an organic solvent N-Methyl-2-Pyrrolidone(NMP)and a triblock polymers in the frequency range from 0.01Hz to 1MHz.The results indicate a dielectric relaxation in the hectohertz region.Individually,both E7 and NMP have rather large low frequency conductivities;however,the low frequency(0.01–10Hz)behavior of the mixtures has no such behavior.We attribute this behavior to an ion getter effect of the triblock polymer surfactant.Optimized ternary mixtures obtain a real dielectric constant near 230,and loss tangent less than 0.05 at frequencies near 10mHz.

Liquid crystal-templated chiral nanomaterials: from chiral plasmonics to circularly polarized luminescence

Chiral nanomaterials with intrinsic chirality or spatial asymmetry at the nanoscale are currently in the limelight of both fundamental research and diverse important technological applications due to their unprecedented physicochemical characteristics such as intense light-matter interactions, enhanced circular dichroism, and strong circularly polarized luminescence. Herein, we provide a comprehensive overview of the state-of-the-art advances in liquid crystal-templated chiral nanomaterials. The chiroptical properties of chiral nanomaterials are touched, and their fundamental design principles and bottom-up synthesis strategies are discussed. Different chiral functional nanomaterials based on liquid-crystalline soft templates, including chiral plasmonic nanomaterials and chiral luminescent nanomaterials, are systematically introduced, and their underlying mechanisms, properties, and potential applications are emphasized. This review concludes with a perspective on the emerging applications, challenges, and future opportunities of such fascinating chiral nanomaterials. This review can not only deepen our understanding of the fundamentals of soft-matter chirality, but also shine light on the development of advanced chiral functional nanomaterials toward their versatile applications in optics, biology, catalysis, electronics, and beyond.

等离子体处理过的基板上液晶平行取向的两种模式

我们提出了一种用于液晶盒的新取向工艺,可以得到0或非0的预倾角。这项工艺是用定向的等离子体流倾斜辐照基板。我们用一个阳极层发射器(anodelagerthruster)作为等离子体辐射源,以产生层状的等离子体流。它适合于处理大面积基板,可以处理有机(聚合物)和无机(玻璃,ITO)层。等离子体流辐照可以得到两种类型的液晶取向:(1)最可及(择优)取向轴位于离子束方向和基板法线组成的入射平面上;(2)最可及取向轴垂直于入射面。随着照射总剂量的增加,取向方向可以从类型(1)向类型(2)转变。在第一种取向模式中,可以通过改变工艺参数,如入射角、离子流密度和离子能等来改变预倾角。第二种取向模式的特征是预倾角为0。第一种模式的方位锚泊能系数相对较弱(W=10-3 Erg/cm2),而第二种类型锚泊能很强(W>10-1 Erg/cm2),与摩擦聚合物基板相当。两种模式的取向特征可以用来产生满足所需参数的取向,和构图(pattern)液晶盒基板。这种工艺方法可以克服传统摩擦工艺的某些缺点。

Stretchable and self-healable spoof plasmonic meta-waveguide for wearable wireless communication system

Microwave transmission lines in wearable systems are easily damaged after frequent mechanical deformation,posing a severe threat to wireless communication.Here,we report a new strategy to achieve stretchable microwave transmission lines with superior reliability and durability by integrating a self-healable elastomer with serpentine-geometry plasmonic meta-waveguide to support the spoof surface plasmon polariton(SSPP).After mechanical damage,the self-healable elastomer can autonomously repair itself to maintain the electromagnetic performance and mechanical strength.Meanwhile,the specially designed SSPP structure exhibits excellent stability and damage resistance.Even if the self-healing process has not been completed or the eventual repair effect is not ideal,the spoof plasmonic meta-waveguide Can still maintain reliable performance.Self-healing material enhances strength and durability,while the SSPP improves stability and gives more tolerance to the self-healing process.Our design coordinates the structural design with material synthesis to maximize the advantages of the SSPP and self-healing material,signifcantly improving the relability and durability of stretchable microwave transmission lines.We also perform communication quality experiments to demonstrate the potential of the proposed meta-waveguide as interconnects in future body area network systems.

Circularly polarized luminescent self-organized helical superstructures:From materials and stimulus-responsiveness to applications

Circularly polarized luminescence(CPL)has gained considerable attention in various systems and has rapidly developed into an emerging research field.To meet the needs of actual applications in diverse fields,a high luminescence dissymmetry factor(glum)and tunable optical performance of CPL would be the most urgent pursuit for researchers.Accordingly,many emerging CPL materials and various strategies have been developed to address these critical issues.Emissive cholesteric liquid crystals(CLCs),that is,luminescent self-organized helical superstructures,are considered to be ideal candidates for constructing CPL-active materials,as they not only exhibit high glum values,but also enable flexible optical control of CPL.This review mainly summarizes the characteristics of CPL based on CLCs as the bulk phase doped with different emitters,including aggregated induced emission molecules,conventional organic small molecules,polymer emitters,metal-organic complex emitters,and luminescent nanoparticles.In addition,the recent significant progress in stimulus-responsive CPL based on emissive CLCs in terms of several types of stimuli,including light,electricity,temperature,mechanical force,and multiple stimuli is presented.Finally,a short perspective on the opportunities and challenges associated with CPL-active materials based on the CLC field is provided.This review is anticipated to offer new insights and guidelines for developing CLC-based CPL-active materials for broader applications.

A high mobility air-stable n-type organic small molecule semiconductor with high UV-visible-to-NIR photoresponse

An organic semiconductor with high carrier mobility and efficient light absorption over a wide spectral range is of the most important yet challenging material for constructing a broadband responsive organic photodetector.However,the development of such organic semiconductors,especially for air-stable n-type organic small molecule semiconductors,is still at an early stage.Here we report the fabrication of high-performance n-type semiconducting crystalline nanosheets and the development of air-stable field-effect transistors,phototransistors,with high response over a broad spectrum.The n-type small molecule semiconductor is assembled into a crystalline nanosheet based on the solvent-phase interfacial self-assembly method.N-type field-effect transistors with high electron mobility are fabricated and their electrical performances exhibit excellent air stability.Impressively,the demonstrated phototransistors exhibit an ultrahigh responsivity over a wide spectral range from 365 to 940 nm,with a maximum photoresponsivity of 9.2×10^(5) AW-1 and specific detectivity of 5.26×10^(13) Jones,which is the best performance among the reported n-type organic small molecule-based phototransistors.

具有超高抗疲劳性能的液态金属增强型液晶弹性体材料

液晶弹性体材料内在的低交联密度特性导致其抗疲劳性能差,严重影响了此类材料在工业上的应用前景.本文报道了一种液态金属增强型液晶弹性体材料,通过将5 wt%液态金属纳米微粒(平均直径:约195 nm)引入液晶弹性体网络,可以显著增强液晶弹性体复合材料的力学性能,特别是超高的抗疲劳性能.该复合材料能够在大应变范围(应变幅度范围高达70%)内承受10,000次拉伸循环和2000次连续可逆致动形变,同时展现出大致动应变(最大致动应变:55%)、大致动应力(1.13 MPa)、完全可逆的热/光驱动性和常温下的自修复功能.该液态金属增强型液晶弹性体材料有望在高载荷致动器领域实现工业化应用.

Electrically tunable helicity of cholesteric heliconical superstructure [Invited]

The dynamic manipulation of the helicity in a cholesteric helical superstructure could enable precise control over its physical and chemical properties, thus opening numerous possibilities for exploring multifunctional devices.When cholesteric material satisfies the sufficiently small bending elastic effect, an electrically induced deformation named the cholesteric heliconical superstructure is formed. Through theoretical and numerical analysis, we systematically studied the tunable helicity of the heliconical superstructure, including the evolution of the corresponding oblique angle and pitch length. To further confirm the optical properties, Berreman’s 4 × 4 matrix method was employed to numerically analyze the corresponding structure reflection under the dual stimuli of chirality and electric field.