- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
In Vitro Bioactivity and Biocompatibility of Bio-Inspired Ti-6Al-4V Alloy Surfaces Modified by Combined Laser Micro/Nano Structuring
摘要： The bioactivity and biocompatibility play key roles in the success of dental and orthopaedic implants. Although most commercial implant systems use various surface microstructures, the ideal multi-scale topographies capable of controlling osteointegration have not yielded conclusive results. Inspired by both the isotropic adhesion of the skin structures in tree frog toe pads and the anisotropic adhesion of the corrugated ridges on the scales of Morpho butter?y wings, composite micro/nano-structures, including the array of micro-hexagons and oriented nano-ripples on titanium alloy implants, were respectively fabricated by microsecond laser direct writing and femtosecond laser-induced periodic surface structures, to improve cell adherence, alignment and proliferation on implants. The main di?erences in both the bioactivity in simulated body ?uid and the biocompatibility in osteoblastic cell MC3T3 proliferation were measured and analyzed among Ti-6Al-4V samples with smooth surface, micro-hexagons and composite micro/nano-structures, respectively. Of note, bioinspired micro/nano-structures displayed the best bioactivity and biocompatibility after in vitro experiments, and meanwhile, the nano-ripples were able to induce cellular alignment within the micro-hexagons. The reasons for these di?erences were found in the topographical cues. An innovative functionalization strategy of controlling the osteointegration on titanium alloy implants is proposed using the composite micro/nano-structures, which is meaningful in various regenerative medicine applications and implant ?elds.
关键词： bioinspired surfaces,biocompatibility,cell adherence,femtosecond laser,bioactivity,cell alignment,Ti-6Al-4V,LIPSS
更新于2025-09-19 17:13:59
-
Counterion‐Switched Reversibly Hydrophilic and Hydrophobic TiO <sub/>2</sub> ‐Incorporated Layer‐By‐Layer Self‐Assembled Membrane for Nanofiltration
摘要： The manipulation of surface wettability has been regarded as an efficient strategy to improve the membrane performances. Herein, the counterion-switched reversibly hydrophilic and hydrophobic surface of TiO2-loaded polyelectrolyte membrane are prepared by layer-by-layer assembly of poly(sodium 4-styrene sulfonate) (PSS) and poly(diallydimethyl-ammoniumchloride (PDDA) containing TiO2@PDDA nanoparticles (NPs) on the hydrolyzed polyacrylonitrile (PAN) substrate membrane. The obtained polyelectrolyte multilayer (PEM) membranes [PEM-TiO2]4.5+X? (X? = Cl?, PFO? [perfluorooctanoate] etc.) show different hydrophilicity and hydrophobicity with various counterions. The integration of TiO2 NPs obviously improves the wettability and nanofiltration (NF) performance of PEM membrane for (non)aqueous system of dyes (crystal violet, eriochrome black T) with a high recyclability. The highly hydrophilic [PEM-TiO2]4.5+Cl? (water contact angle [WCA]: 13.2 ± 1.8°) and hydrophobic [PEM-TiO2]4.5+PFO? (WCA: 115.4 ± 2.3°) can be reversibly switched via counterion exchange between Cl? and PFO?, verifying the surface with a reversible hydrophilic–hydrophobic transformation. For such membranes, the morphology, wettability, and NF performance rely on the loading of TiO2@PDDA NPs and surface counterion. Meanwhile, the motion and interaction of water or ethanol in the hydrophilic or hydrophobic membrane are revealed by low-field nuclear magnetic resonance. This work provides a facile and rapid approach to fabricate smart and tunable wetting surface for potential utilization in (non)aqueous NF separation.
关键词： (non)aqueous nanofiltration,TiO2-incoporated polyelectrolyte multilayer membranes,counterion-switched surfaces,LbL self-assembly,reversible wettability
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Las Vegas, NV, USA (2019.5.28-2019.5.31)] 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Fully Additively Manufactured Tunable Active Frequency Selective Surfaces with Integrated On-package Solar Cells for Smart Packaging Applications
摘要： A ?rst-of-its-kind fully inkjet-printed electronically tunable active ?exible frequency selective surface (FSS) using varactors with integrated on-package solar cells is presented in this paper. Each varactor is biased by a dedicated on-package inkjet-printed solar cell using a low-temperature fabrication process. The solar cell changes its output voltage with variation in light intensities that eventually leads to a change in capacitance of the varactor and overall frequency response of the FSS. The proposed design eliminates the use of labor intensive biasing network, bulky power supply and micro-controllers to tune the FSS frequency response. These structures presents an autonomous, ultra low cost on-package RF shielding mechanism for next-generation of system-on-chip packaging applications that can be tuned on-demand at different frequency bands by simple variation of incident light intensities. Thus making them useful for a wide range of terrestrial, outer-space and EMI shielding applications.
关键词： Additive manufacturing,tunable FSS,solar cells,Frequency selective surfaces,varactors,tunable RF structures,inkjet printing
更新于2025-09-16 10:30:52
-
Self-assembled monolayers of polyoxovanadates with phthalocyaninato lanthanide moieties on gold surfaces
摘要： The two first representatives of phthalocyaninato (Pc) lanthanide-ligated polyoxovanadate cages {[V12O32(Cl)](LnPc)n}n(cid:2)5 (n = 1 or 2, Ln = Yb3+) were synthesised and fully characterised. These magnetic complexes form two-dimensional self-assembled monolayers exhibiting electrical conductivity on gold substrate surfaces, as assessed by using an EGaIn tip.
关键词： gold surfaces,electrical conductivity,phthalocyaninato lanthanide,polyoxovanadates,self-assembled monolayers
更新于2025-09-16 10:30:52
-
Mathematical Modelling of Electrically Controlled Filters of Microwave, subTHz and THza??bands on the Base of Grapheneand-Dielectric Multilayer Structure
摘要： Report is devoted to investigations of graphene meta–surfaces for the transmission of radiation induced by plasmons in subTHz and THz ranges, cell of which consists of structures based on graphene ring and graphene nano–tape. It create regimes of radiation transmission – transparency windows induced by electric dipole resonances. Resonant frequency of transparency window can be dynamically tuned in wide band of subTHz and THz bands by changing the chemical potential (Fermi energy) of graphene by applying external electric field (gating) instead of re–fabricating of structures. Questions of possibilities of electronic controlled filters creating of subTHz and THz bands grounded on different configurations of graphene meta–surfaces are discussed; their characteristics and frequency dependencies are investigated. Mathematical modelling and electrodynamic calculation of the filters characteristics of subTHz and THz bands grounded on multilayer structures of “graphene–dielectric” type are carried out. From results of mathematical modelling it follows that periodic layered microstructures “graphene–dielectric” type can be used for creation of subTHz and THz bands broadband filters of planar construction, controlling by electric field and fast tuning at small changes in Fermi energy level of graphene.
关键词： multilayer structures,filters,subTHz,plasmonic,chemical potential,electric field,graphene,meta-surfaces,electric dipole resonances,THz,Fermi energy
更新于2025-09-16 10:30:52
-
Q-Switch Nd:YAG Laser-Assisted Decontamination of Implant Surface
摘要： Peri-implantitis (PI) is an inflammatory disease of peri-implant tissues, it represents the most frequent complication of dental implants. Evidence revealed that microorganisms play the chief role in causing PI. The purpose of our study is to evaluate the cleaning of contaminated dental implant surfaces by means of the Q-switch Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser and an increase in temperature at lased implant surfaces during the cleaning process. Seventy-eight implants (titanium grade 4) were used (Euroteknika, Sallanches, France). Thirty-six sterile implants and forty-two contaminated implants were collected from failed clinical implants for different reasons, independent from the study. Thirty-six contaminated implants were partially irradiated by Q-switch Nd:YAG laser (1064 nm). Six other contaminated implants were used for temperature rise evaluation. All laser irradiations were calibrated by means of a powermetter in order to evaluate the effective delivered energy. The irradiation conditions delivered per pulse on the target were effectively: energy density per pulse of 0.597 J/cm2, pick powers density of 56 mW/cm2, 270 mW per pulse with a spot diameter of 2.4 mm, and with repetition rate of 10 Hz for pulse duration of 6 ns. Irradiation was performed during a total time of 2 s in a non-contact mode at a distance of 0.5 mm from implant surfaces. The parameters were chosen according to the results of a theoretical modeling calculation of the Nd:YAG laser fluency on implant surface. Evaluation of contaminants removal showed that the cleaning of the irradiated implant surfaces was statistically similar to those of sterile implants (p-value ≤ 0.05). SEM analysis confirmed that our parameters did not alter the lased surfaces. The increase in temperature generated at lased implant surfaces during cleaning was below 1 °C. According to our findings, Q-switch Nd:YAG laser with short pulse duration in nanoseconds is able to significantly clean contaminated implant surfaces. Irradiation parameters used in our study can be considered safe for periodontal tissue.
关键词： biofilm,dental implant,peri-implantitis,titanium surfaces decontamination
更新于2025-09-16 10:30:52
-
Electronic Structure of Sr <sub/>1?</sub><i> <sub/>y</sub></i> Ca <i> <sub/>y</sub></i> Fe <sub/>2</sub> (As <sub/>1?</sub><i> <sub/>x</sub></i> P <i> <sub/>x</sub></i> ) <sub/>2</sub> ( <i>x</i> = 0.25, <i>y</i> = 0.08) Revealed by Angle-Resolved Photoemission Spectroscopy
摘要： We have investigated the electronic structure of Sr1?yCayFe2(As1?xPx)2 (x = 0.25, y = 0.08) by means of angle-resolved photoemission spectroscopy. From the comparison with the results of BaFe2(As1?xPx)2, the effects of smaller structural anisotropy (c/a) on the Fermi surfaces (FSs) and the gap structures are discussed. The observed FSs have three dimensional shapes. One of the hole FSs is strongly warped between the Γ and Z points, and the innermost FS observed at the Z point disappears at the Γ point, which is similar to the FS features of SrFe2(As1?xPx)2 (x = 0.35). In the superconducting state, the node like gap-minimum is present for the dxy electron FS near the X point, while the gaps around the other high symmetry points are isotropic. Several theoretical models based on the spin and/or the orbital fluctuation are examined to explain all these experimental results.
关键词： spin fluctuation,orbital fluctuation,electronic structure,Fermi surfaces,angle-resolved photoemission spectroscopy,superconducting gap
更新于2025-09-16 10:30:52
-
Subwavelength Hexahedral Plasmonic Scatterers: History, Symmetries, and Resonant Characteristics
摘要： In this work, we investigate the resonant characteristics of hexahedral (cubical) inclusions at the plasmonic domain. After an introduction to the notion of superquadric surfaces, i.e., surfaces that model various versions of a rounded cube, we present the main resonant spectrum and the surface distributions for two particular cases of a smooth and a sharp cube in the plasmonic domain. We present a historical comparative overview of the main contributions available since the 1970s. A new categorization scheme of the resonances of a cube is introduced, based on symmetry considerations. The obtained results are compared against several recent works, exposing that the higher-order modes are extremely susceptible to both the choice of sharpness of the cube and the modeling mesh. This work can be readily used as a reference for both historical and contemporary studies of the plasmonic aspects of a cube.
关键词： electrostatic scattering,history of plasmonic cubes,plasmonic cube,superquadric surfaces,localized plasmonic resonances,plasmonic particles
更新于2025-09-16 10:30:52
-
Compact three-dimensional bandpass FSS with high selectivity based on split square coaxial waveguide
摘要： In this Letter, a compact three-dimensional (3D) frequency selective surface (FSS), exhibiting a bandpass filtering response with high selectivity, is proposed based on the split square coaxial waveguide (SSCW). The unit cell of the presented 3D FSS consists of one parallel-plate waveguide propagation path and one SSCW propagation path. In the SSCW path, two identical short SCWs are produced by employing a centred annular slot. Each short SCW intrinsically provides a square slot resonance. Owing to the electromagnetic coupling between these two square slot resonances, original single square slot resonant mode will split into even-/odd-resonant modes, resulting in a flat passband with two transmission poles. Moreover, two transmission zeros located at both sides of the passband are introduced for high selectivity, because the electromagnetic waves passing through these two different paths are combined out of phase. By investigating the electric-field distributions at the frequencies of the transmission zeros/poles, the operating principle of the proposed 3D FSS is described. A prototype of the proposed 3D FSS is fabricated and measured. The measured results show that the proposed design can achieve a stable response under the incident angles up to 60° for both TE and TM polarisations.
关键词： frequency selective surfaces,bandpass filtering,compact,split square coaxial waveguide,high selectivity
更新于2025-09-16 10:30:52
-
Hybrid plasmonic metasurfaces
摘要： Plasmonic metasurfaces based on ensembles of distributed metallic nanostructures can absorb, scatter, and in other ways shape light at the nanoscale. Forming hybrid plasmonic metasurfaces by combination with other materials opens up for new research directions and novel applications. This perspective highlights some of the recent advancements in this vibrant research field. Particular emphasis is put on hybrid plasmonic metasurfaces comprising organic materials and on concepts related to switchable surfaces, light-to-heat conversion, and hybridized light-matter states based on strong coupling.
关键词： strong coupling,hybrid plasmonic metasurfaces,organic materials,light-to-heat conversion,switchable surfaces
更新于2025-09-16 10:30:52