- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Possibilities of Dry and Lubricated Friction Modification Enabled by Different Ultrashort Laser-Based Surface Structuring Methods
摘要： In this contribution we report on the possibilities of dry and lubricated friction modification introduced by different laser surface texturing methods. We compare the potential of Laser-Induced Periodic Surface Structures and Laser Beam Interference Ablation on 100Cr6 steel in a linear reciprocating ball-on-disc configuration using 100Cr6 steel and tungsten carbide balls with load forces between 50 mN and 1000 mN. For dry friction, we find a possibility to reduce the coefficient of friction and we observe a pronounced direction dependency for surfaces fabricated by Laser Beam Interference Ablation. Furthermore, Laser-Induced Periodic Surface Structures result in a load-dependent friction reduction for lubricated linear reciprocating movements. This work helps to identify the modification behaviour of laser generated micro structures with feature sizes of approximately 1 μm and reveals new possibilities for surface engineering
关键词： lubricated friction,smart surfaces,laser surface texturing,laser beam interference ablation,laser-induced periodic surface structures,dry friction
更新于2025-11-21 11:18:25
-
Room Temperature Synthesis of Germanium Oxide Nanofilaments and Their Potential Use as Luminescent Self‐Cleaning Surfaces
摘要： Germanium oxide nanofilaments (GNFs) have been synthesized under ambient conditions from the gas phase using germanium tetrachloride as a precursor. Non-crystalline GNFs synthesized by this procedure are 1-10 μm in length and 80-110 nm in diameter applying Droplet Assisted Growth and Shaping (DAGS) Chemistry. The relative humidity has been adjusted at various values in order to demonstrate the crucial role of humidity in the gas phase for the nanofilament synthesis. The novel GNFs show a strong luminescence emission in the ultra-violet and light blue region. In addition, a self-cleaning and superhydrophobic properties could be introduced in the luminescent GNF nanofilaments by simple treatment with silane molecules.
关键词： silicone nanofilaments,chemical vapor deposition,DAGS chemistry,germanium oxide nanofilaments,self-cleaning surfaces
更新于2025-11-14 15:18:02
-
Dewetting and photochemical crosslinking of adhesive pads onto lithographically patterned surfaces
摘要： The design of structured adhesive interfaces can be realized by dewetting of a liquid adhesive onto substrates with hydrophilic and hydrophobic domains followed by photochemical crosslinking. The latter allows the creation of well-defined arrays of confined adhesive pads with a controlled geometry. In a first step, the surfaces are covered by a hydrophobic film and lithographically patterned through a mask with an array of spots with diameter of 2 mm. The adhesive can consequently be locally deposited by a dosing syringe and remains confined within the hydrophilic spots. By defining the volume of the adhesive droplets, the contact angle and height of the adhesive pads are controlled through pinning at the hydrophilic/hydrophobic interface, which prevents further spreading. Alternatively, the dip coating and spontaneous dewetting of liquid adhesive over the patterned surface provide a continuous fabrication method for adhesive pad arrays. In a second step, the geometry of the deposited adhesive pads is stabilized by partial crosslinking during different times under UV light. Finally, an adhesive joint is created by applying the counterface followed by full cross-linking. The adhesive strength and mechanical performance are further optimized by considering different crosslinking times and pattern designs.
关键词： adhesives,surfaces and interface,photopolymerization
更新于2025-09-23 15:23:52
-
Micro Grating Deposition on Non-Planar Surfaces by Polymer-Assisted Transfer Printing
摘要： By spin-coating a few hundred of nanometer thick poly(methyl methacrylate) (PMMA) film on a micron or a sub-micron scale structure, the structure can be transferred on an arbitrary substrate. More precisely, by using a thin PMMA support layer and releasing the structure from the transient substrate into water, the PMMA with the structure can be collected on a desired substrate. Here, this technique is demonstrated to be suitable for transferring metallic binary grating and few-layer Bragg gratings from flat substrates onto 3D-printed convex lenses. Moreover, the thin PMMA film is sufficiently strong to support centimeter size free-standing areas. This enables fabrication of 1.5 μm thick, free-standing structure of a Bragg-grating with PMMA. Thus, the presented technique provides a powerful tool for transfer printing of micron scale structures.
关键词： transfer printing,non-planar surfaces,free-standing structures,microstructure transfer
更新于2025-09-23 15:23:52
-
Automatic mapping of cracking patterns on concrete surfaces with biological stains using hyper-spectral images processing
摘要： Despite all technological advances, mapping cracks on concrete structures mostly remains to be evaluated through sketches based on on-site observation and photographs. Methods based on image processing have been developed with clear advantages. However, most studies rely on perfectly identified areas or on single cracks without any other pathologies, being therefore unsuitable for on-site application. In addition, the accuracy is not usually quantified due to the absence of ground-truth. Thus, methods for automatic mapping of cracking patterns, sufficiently robust to deal with the surrounding pathologies, are of great interest. The Super Cluster-Crack method (SC-Crack method) is herein presented. It was developed for crack detection in concrete surfaces, with biological stains, by processing hyperspectral images. SC-Crack performs k-means clustering, followed by grouping clusters to composing a super cluster that stands for the cracks. The method was calibrated and validated by classifying hyperspectral images of concrete specimens, within bandwidths of 25 nm in a wavelength range between 425 nm and 950 nm. Results are discussed by comparison with the ground-truth image. Finally, the super cluster composition is also validated. The SC-Crack method performs successfully both on clean and on surface with biological stains. In the latter case, hyperspectral images help to avoid mixing biological stains with crack pattern. Concerning the main goal of mapping the cracking pattern, the method performs perfectly on concrete clean surfaces, allowing to detect all the crack branches. In the case of surface with biological stains, the SC-Crack also detects the majority of cracking pattern, except for the thinner branches.
关键词： image processing,concrete surfaces,super cluster,cracking pattern,hyper-spectral image,automatic mapping
更新于2025-09-23 15:23:52
-
[IEEE 2018 International Flexible Electronics Technology Conference (IFETC) - Ottawa, ON, Canada (2018.8.7-2018.8.9)] 2018 International Flexible Electronics Technology Conference (IFETC) - Electromagnetic Engineered Surface Gratings at 5G Bands Using Printed Electronics
摘要： Electromagnetic engineered surfaces (EES) are a recently introduced concept with the implementation goal of controlling the electromagnetic scattering in communications environments. This paper will focus on EES design techniques to enable the passive extension of line of sight (LoS) coverage into non-LoS regions.
关键词： coverage,electromagnetic engineered surfaces (EES),mm-wave,5G,gratings,communications environment
更新于2025-09-23 15:23:52
-
[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Generating a Perspective Image from a Panoramic Image by the Swung-to-Cylinder Projection
摘要： This paper proposes a swung-to-cylinder projection model for mapping a sphere to a plane. It can be used to create a semi-perspective image from a panoramic image. The model has two steps. In the first step, the sphere is projected onto a swung surface constructed by a circular profile and a rounded rectangular trajectory. In the second step, the projected image on the swung surface is mapped onto a cylinder through the perspective projection. We also propose methods for automatically determining proper parameters for the projection model based on image content. The proposed model is simple, efficient and easy to control. Experiments and analysis demonstrate its effectiveness.
关键词： swung surfaces,Projection models
更新于2025-09-23 15:22:29
-
A hybrid perchlorate with a low band gap: Crystal structure, physicochemical characterization and Hirshfeld surfaces study
摘要： The anhydrous hybrid material (C6H10N2) (ClO4)2 has been synthesized by the slow evaporation method. X-ray diffraction on a single crystal shows that this compound crystallizes in the monoclinic system with the centrosymmetric space group P21/c. The 2D supramolecular network is stabilized by NeH/O interactions whereas the van der Waals contacts play a key role in the consolidation of the 3D packing as verified by Hirshfeld surface analysis in combination with 2D fingerprint plots. The 13C CP-MAS NMR spectrum is in agreement with the X-ray structure. DFT calculations allowed the attribution of the NMR peaks. FT-IR spectrum confirms the presence of various functional groups in the synthesized material. The thermal stability, phase transition and degradation, of this material has been studied using simultaneous TG-DTA. The gap between the frontier molecular orbitals is about 1.53 eV suggesting that the studied compound is a semiconducting material.
关键词： Crystal structure,Spectroscopic study: thermal analysis,Hirshfeld surfaces
更新于2025-09-23 15:22:29
-
Analysis of Sustainable Materials for Radiative Cooling Potential of Building Surfaces
摘要： The main goal of this paper is to explore the radiative cooling and solar heating potential of several materials for the built environment, based on their spectrally-selective properties. A material for solar heating, should have high spectral emissivity/absorptivity in the solar radiation band (within the wavelength range of 0.2–2 μm), and low emissivity/absorptivity at longer wavelengths. Radiative cooling applications require high spectral emissivity/absorptivity, within the atmospheric window band (8–13 μm), and a low emissivity/absorptivity in other bands. UV-Vis spectrophotometer and FTIR spectroscopy, are used to measure, the spectral absorption/emission spectra of six different types of materials. To evaluate the radiative cooling potential of the samples, the power of cooling is calculated. Heat transfer through most materials is not just a surface phenomenon, but it also needs a volumetric analysis. Therefore, a coupled radiation and conduction heat transfer analysis is used. Results are discussed for the selection of the best materials, for different applications on building surfaces.
关键词： sustainable materials,coupled radiation-conduction heat transfer,built environment,spectrally-selective surfaces,radiative cooling,roofs
更新于2025-09-23 15:22:29
-
[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Dual Polarized Lens Antenna Based on Multimode Huygens' Surfaces
摘要： A dual-polarized lens antenna system based on isotropic Huygens’ Surfaces is proposed for 12 GHz applications. The multimode resonances of the unit cell of the surface lens are detailed analyzed. Then, a broadband dual-polarized microstrip antenna is combined with the lens as the primary feed to form a lens antenna system. The simulated results demonstrate that the prototype can realize input ports isolation of more than 25 dB, and the gain of more than 17.5 dB over a wide bandwidth (11 ~ 13.5 GHz).
关键词： Multimode resonance,Huygens’ surfaces,Lens antenna,Dual Polarization
更新于2025-09-23 15:22:29