- 标题
- 摘要
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- 实验方案
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Quasi-3D Perfect Absorber Based on the Self-Similar Parasitic Elements as an Optical Sensor with Tunable Attributes for Near-Infrared Application
摘要： We have designed a novel self-similar plasmonic perfect absorber with a quasi-three-dimensional (3D) shape based on parasitic elements, which is useful as a refractive index sensor for near-infrared applications. In order to achieve tunable attributes, we have applied the liquid crystal medium to provide a tunable structure which can be considered to control the absorption parameter and resonances. In fact, we have proposed a self-similar structure to obtain a multi-band structure in the range of 800–1600 nm with an absorption value up to 99.8%. The basic model is a single cross element, while each quarter is ?lled up by L-shaped elements by forming a tapered shape like a pyramidal in which the elements are arranged from large to small with various heights and lengths which creates a ziggurat form. So this structure can provide a quad-band absorber which we have implemented as a refractive index sensor with a much higher ?gure of merit (FOM) in comparison to the ?at formations. For the ?nal structure, the maximum values of the FOM and sensitivity (S) are 24,560 RIU?1 and 660 nm RIU?1, respectively.
关键词： plasmonic,liquid crystal,Absorber,near-infrared
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Singapore, Singapore (2019.12.10-2019.12.13)] 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Two-Dimensional Electronically Controlled Scanning Phased Array Antenna Based on Liquid Crystal Material
摘要： In this paper, a two-dimensional electronically controlled scanning phased array antenna based on liquid crystal material is introduced. The structure consists of a 2×2 microstrip patch antenna array, a continuously variable helical folded delay line phase shifter, a RF feed and a bias network. The suspended stripline power divider, ground coplanar waveguide-suspended stripline transition structure and broadband patch antenna are studied respectively. The Ka-band LC passive phased array is developed by cascading the above circuits. The simulation results show that by tuning the excitation phases of each unit, the two-dimensional phase scan of the array is realized, the scanning angle is greater than ±30°, and the -10dB bandwidth of the array is larger than that of 4GHz.
关键词： Phased array,electronic scanning,liquid crystal
更新于2025-09-23 15:19:57
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3a??Dimensional Charge Transport Pathway in Organic Solar Cells via Incorporation of Discotic Liquid Crystal Columns
摘要： 2,3,6,7,10,11-hexaacetoxytriphenylene (HATP) as a discotic liquid crystals with high mobility can aggregate into columns structure on PEDOT:PSS in organic solar cells. HATP columns facilitate the formation of 3-dimensional charge transport pathway, which increase the intermolecular charge transport and mobility. Additionally, the triplet exciton, trap state and bimolecular recombination is suppressed. Thus, the JSC is increased significantly for (non-) fullerene system.
关键词： discotic liquid crystal,organic solar cells,mobility,columnar structure,3-dimensional charge transport
更新于2025-09-23 15:19:57
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SIMULATION OF CO-PLANAR WAVEGUIDE LIQUID CRYSTAL BASED PHASE SHIFTER
摘要： This paper discussed the design and performances of a liquid crystal phase shifter that can be used in tuning devices. Tuning devices growth with the demand in the emerging in telecommunication system. Tuning devices with smooth continuous phase shifting at low cost and compact size would be an advantage. This paper proposed a phase shifter using 5CB liquid crystal material. The advantages of using the material is the smoothness and continuity of the transitions in the phase shift. It is done by having a structure with cavity filled with the liquid crystal and applied with certain voltage that can be changed. The changes in voltage would change the applied electric field, and thus would change the permittivity of the material. The changes would affect the wave propagation and thus contribute to the phase shifting. The performance of the phase shifter was tested by means of simulation using CST Suite 2014 software. The results show that the higher the frequency, the higher the phase shift would occur. The highest FoM achieved is 68 (deg/dB) at 8 GHz. A phase shifter with smooth and continuous phase shift can be used as the feeding network in an array scanning antennas systems.
关键词： tunable materials,liquid crystal,FoM,CPW,Phase shifter
更新于2025-09-23 15:19:57
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A Light-Powered Ultralight Tensegrity Robot with High Deformability and Load Capacity
摘要： Traditional hard robots often require complex motion-control systems to accomplish various tasks, while applications of soft-bodied robots are limited by their low load-carrying capability. Herein, a hybrid tensegrity robot composed of both hard and soft materials is constructed, mimicking the musculoskeletal system of animals. Employing liquid crystal elastomer–carbon nanotube composites as artificial muscles in the tensegrity robot, it is demonstrated that the robot is extremely deformable, and its multidirectional locomotion can be entirely powered by light. The tensegrity robot is ultralight, highly scalable, has high load capacity, and can be precisely controlled to move along different paths on multiterrains. In addition, the robot also shows excellent resilience, deployability, and impact-mitigation capability, making it an ideal platform for robotics for a wide range of applications.
关键词： liquid crystal elastomers,tensegrity,robots
更新于2025-09-23 15:19:57
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Curvature-Induced Twist in Homeotropic Nematic Tori
摘要： We confine a nematic liquid crystal with homeotropic anchoring to stable toroidal droplets and study how geometry affects the equilibrium director configuration. In contrast to the case of cylindrical confinement, we find that the equilibrium state is chiral—a twisted and escaped radial director configuration. Furthermore, we find that the magnitude of the twist distortion increases as the ratio of the ring radius to the tube radius decreases; we confirm this with computer simulations of optically polarized microscopy textures. In addition, numerical calculations also indicate that the local geometry indeed affects the magnitude of the twist distortion. We further confirm this curvature-induced twisting using bent cylindrical capillaries.
关键词： twist distortion,nematic liquid crystal,curvature-induced twisting,chiral,toroidal droplets,homeotropic anchoring
更新于2025-09-23 15:19:57
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Transistor Characteristics of Single Crystalline C<sub>8</sub>-BTBT Grown in Coated Liquid Crystal Solution on Photo-Alignment Films
摘要： We examined single crystal growth of benzothienobenzothiophene-based organic semiconductors by solution coating method using liquid crystal and investigated its electrical characteristics. As the results, we revealed that the averaged mobility in the saturation region reached 2.08 cm2/Vs along crystalline b-axis, and 1.08 cm2/Vs along crystalline a-axis.
关键词： organic semiconductor,liquid crystal solvent,single crystal,solution coating,organic field effect transistor
更新于2025-09-19 17:15:36
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Measuring of nonlinear properties of spatial light modulator with different wavelengths
摘要： The non-linear optical properties of Spatial Light Modulator(SLM) represented by Nonlinear Refractive Index (NLR) and nonlinear Absorption coefficient has been measured in this work using highly sensitive method known as Z-scan technique for different wavelengths (red and green). The capability to do instant measurements of different nonlinear optical parameters lead to consider these techniques as a one of the most desired and effective methods that could apply for different materials. The results showed that the NLR were in the same power for the different wavelengths while the nonlinear absorption is higher in case of green laser.
关键词： Z-scan technique,Nematic Liquid Crystal,SLM
更新于2025-09-19 17:15:36
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1H NMR study of molecular order and dynamics in CBC9CB Liquid Crystal
摘要： Molecular order and dynamics of the CB-C9-CB liquid crystalline dimer exhibiting the nematic (N) and the twist bend nematic (Ntb) phases were investigated by proton NMR spectroscopy, using fields of 0.78 T and 7.04 T, and relaxometry. The first relaxometry experiments for a very wide Larmor frequency domain (8 kHz - 300 MHz) on this system, using a combination of standard and fast field cycling NMR techniques, were performed. The spectroscopy results in the Ntb phase allowed us to probe the local molecular orientation relative to the Ntb helix axis. The relaxation data were analyzed considering order director fluctuations (ODF), molecular self-diffusion (SD) and local molecular rotations/reorientations (R) relaxation mechanisms. Global fits of theoretical relaxation models, as a function of temperature and Larmor frequency, for the phases under investigation, allowed for the determination of rotational correlation times, diffusion coefficients, viscoelastic parameters, correlation lengths and activation energies (in the case of thermally activated mechanisms). A clear difference between the structures of the N and Ntb phases was detected from the results of proton spin-lattice relaxation through distinct temperature and frequency dependencies' signatures of the collective modes. Significant pre-transitional effects were observed at the N-Ntb phase transition both from relaxometry and spectroscopy data. The experimental results correlate to data and models for comparable liquid crystalline systems.
关键词： molecular dynamics,liquid crystal,nematic phase,twist bend nematic phase,NMR spectroscopy,relaxometry
更新于2025-09-19 17:15:36
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Polymer dispersed nematic liquid crystal films with conical boundary conditions for electrically controllable polarizers
摘要： Polymer dispersed nematic liquid crystal (PDNLC) ?lms with conical boundary conditions at the LC-polymer interface are considered. The conical surface anchoring with tilt angle 40° initiates forming the axial-bipolar director con?guration inside nematic droplets. This droplet structure exhibits the strong scattering of light polarized parallel to the bipolar axis. In the initial state, the bipolar axes in all droplets are oriented randomly, and therefore PDNLC ?lm scatters a light of any polarization. Electric ?eld applied along the ?lm plane orients the bipolar axes unidirectionally in the whole droplet ensemble, that results in its high polarization-dependent transmittance. Such PDNLC ?lms can be used in the electrically controllable linear polarizers characterized by 89% value of the transmittance for the perpendicular polarized light and high extinction ratio 590:1 at the electric ?eld 0.34 V/μm.
关键词： Light polarizer,Nematic droplets,Polymer dispersed liquid crystal ?lms,Scattering anisotropy,Electro-optics
更新于2025-09-19 17:15:36