scholarly journals Digital laser micro- and nanoprinting

Nanophotonics ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Qingfeng Li ◽  
David Grojo ◽  
Anne-Patricia Alloncle ◽  
Boris Chichkov ◽  
Philippe Delaporte
Keyword(s):  
Three Dimensional ◽  
Digital Fabrication ◽  
Two Dimensions ◽  
Minimum Size ◽  
Direct Writing ◽  
3D Objects ◽  
Wide Range ◽  
Macro Scale ◽  
Forward Transfer ◽  
Pros And Cons

AbstractLaser direct writing is a well-established ablation technology for high-resolution patterning of surfaces, and since the development of additive manufacturing, laser processes have also appeared very attractive for the digital fabrication of three-dimensional (3D) objects at the macro-scale, from few millimeters to meters. On the other hand, laser-induced forward transfer (LIFT) has demonstrated its ability to print a wide range of materials and to build functional micro-devices. For many years, the minimum size of laser-printed pixels was few tens of micrometers and is usually organized in two dimensions. Recently, new approaches have been investigated, and the potential of LIFT technology for printing 2D and 3D sub-micrometer structures has become real. After a brief description of the LIFT process, this review presents the pros and cons of the different digital laser printing technologies in the aim of the additive nanomanufacturing application. The transfer of micro- and nano-dots in the liquid phase from a solid donor film appears to be the most promising approach to reach the goal of 3D nanofabrication, and the latest achievements obtained with this method are presented and discussed.

Turbulent three-dimensional dielectric electrohydrodynamic convection between two plates

2012 ◽  
Vol 696 ◽  
pp. 228-262 ◽  
Author(s):  
A. Kourmatzis ◽  
J. S. Shrimpton
Keyword(s):  
Spatial Data ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Energy Budgets ◽  
Turbulent Regime ◽  
Scalar Flux ◽  
Wide Range ◽  
Scalar Variance

AbstractThe fundamental mechanisms responsible for the creation of electrohydrodynamically driven roll structures in free electroconvection between two plates are analysed with reference to traditional Rayleigh–Bénard convection (RBC). Previously available knowledge limited to two dimensions is extended to three-dimensions, and a wide range of electric Reynolds numbers is analysed, extending into a fully inherently three-dimensional turbulent regime. Results reveal that structures appearing in three-dimensional electrohydrodynamics (EHD) are similar to those observed for RBC, and while two-dimensional EHD results bear some similarities with the three-dimensional results there are distinct differences. Analysis of two-point correlations and integral length scales show that full three-dimensional electroconvection is more chaotic than in two dimensions and this is also noted by qualitatively observing the roll structures that arise for both low (${\mathit{Re}}_{E} = 1$) and high electric Reynolds numbers (up to ${\mathit{Re}}_{E} = 120$). Furthermore, calculations of mean profiles and second-order moments along with energy budgets and spectra have examined the validity of neglecting the fluctuating electric field ${ E}_{i}^{\ensuremath{\prime} } $ in the Reynolds-averaged EHD equations and provide insight into the generation and transport mechanisms of turbulent EHD. Spectral and spatial data clearly indicate how fluctuating energy is transferred from electrical to hydrodynamic forms, on moving through the domain away from the charging electrode. It is shown that ${ E}_{i}^{\ensuremath{\prime} } $ is not negligible close to the walls and terms acting as sources and sinks in the turbulent kinetic energy, turbulent scalar flux and turbulent scalar variance equations are examined. Profiles of hydrodynamic terms in the budgets resemble those in the literature for RBC; however there are terms specific to EHD that are significant, indicating that the transfer of energy in EHD is also attributed to further electrodynamic terms and a strong coupling exists between the charge flux and variance, due to the ionic drift term.

scholarly journals Three-Dimensional Laser Printing of Macro-Scale Glass Objects at a Micro-Scale Resolution

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 565 ◽  
Author(s):  
Peng Wang ◽  
Wei Chu ◽  
Wenbo Li ◽  
Yuanxin Tan ◽  
Fang Liu ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Laser Pulses ◽  
Fused Silica ◽  
Rapid Expansion ◽  
Ultrafast Laser Pulses ◽  
3D Objects ◽  
Macro Scale ◽  
Powerful Approach ◽  
3D Printing Technique

Three-dimensional (3D) printing has allowed for the production of geometrically complex 3D objects with extreme flexibility, which is currently undergoing rapid expansion in terms of materials, functionalities, as well as areas of application. When attempting to print 3D microstructures in glass, femtosecond laser-induced chemical etching (FLICE)—which is a subtractive 3D printing technique—has proved itself a powerful approach. Here, we demonstrate the fabrication of macro-scale 3D glass objects of large heights up to ~3.8 cm with an identical lateral and longitudinal feature size of ~20 μm. The remarkable accomplishment is achieved by revealing an unexplored regime in the interaction of ultrafast laser pulses with fused silica, which results in depth-insensitive focusing of the laser pulses inside fused silica.

scholarly journals Three-Dimensional Laser Printing of Macro-Scale Glass Objects at a Micro-Scale Resolution

2019 ◽  
Author(s):  
Peng Wang ◽  
Wei Chu ◽  
Wenbo Li ◽  
Yuanxin Tan ◽  
Fang Liu ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Laser Pulses ◽  
Fused Silica ◽  
Ultrafast Laser Pulses ◽  
3D Objects ◽  
Macro Scale ◽  
Powerful Approach ◽  
Printing Technique ◽  
3D Printing Technique

Three-dimensional (3D) printing has allowed for production of geometrically complex 3D objects with extreme flexibility, which is currently undergoing rapid expansions in terms of materials, functionalities, as well as areas of application. When attempting to print 3D microstructures in glass, femtosecond laser induced chemical etching (FLICE) – which is a subtractive 3D printing technique – has proved itself a powerful approach. Here, we demonstrate fabrication of macro-scale 3D glass objects of large heights up to ~3.8 cm with an identical lateral and longitudinal spatial resolution of ~20 μm. The remarkable accomplishment is achieved by revealing an unexplored regime in the interaction of ultrafast laser pulses with fused silica which results in aberration-free focusing of the laser pulses deeply inside fused silica.

scholarly journals 3D Magnetic Reconnection

2010 ◽  
Vol 6 (S271) ◽  
pp. 227-238 ◽  
Author(s):  
Clare E. Parnell ◽  
Rhona C. Maclean ◽  
Andrew L. Haynes ◽  
Klaus Galsgaard
Keyword(s):  
Magnetic Reconnection ◽  
Energy State ◽  
Single Point ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Wide Range ◽  
Field Lines ◽  
Magnetohydrodynamic Models ◽  
The Magnetic Field

AbstractMagnetic reconnection is an important process that is prevalent in a wide range of astrophysical bodies. It is the mechanism that permits magnetic fields to relax to a lower energy state through the global restructuring of the magnetic field and is thus associated with a range of dynamic phenomena such as solar flares and CMEs. The characteristics of three-dimensional reconnection are reviewed revealing how much more diverse it is than reconnection in two dimensions. For instance, three-dimensional reconnection can occur both in the vicinity of null points, as well as in the absence of them. It occurs continuously and continually throughout a diffusion volume, as opposed to at a single point, as it does in two dimensions. This means that in three-dimensions field lines do not reconnect in pairs of lines making the visualisation and interpretation of three-dimensional reconnection difficult.By considering particular numerical 3D magnetohydrodynamic models of reconnection, we consider how magnetic reconnection can lead to complex magnetic topologies and current sheet formation. Indeed, it has been found that even simple interactions, such as the emergence of a flux tube, can naturally give rise to ‘turbulent-like’ reconnection regions.

Design for Additive Manufacturing: Valves Without Moving Parts

2017 ◽  
Author(s):  
A. Gaymann ◽  
F. Montomoli ◽  
M. Pietropaoli
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
Design Method ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Two Dimensions ◽  
Steepest Descent Method ◽  
Wide Range ◽  
Tesla Valve ◽  
Moving Parts

This work presents an innovative design method to obtain valves without moving parts that can be built using additive manufacturing and applied to gas turbines. Additive manufacturing offers more flexibility than traditional manufacturing methods, which implies less constraints on the manufacture of engineering parts and it is possible to build complex geometries like the Tesla valve. The Tesla valve is a duct that shows a diodicity behavior: it allows a fluid to flow in one direction with lower losses than in the other one. Unfortunately the design of the Tesla valve is two dimensional and it relies on the designer experience to obtain good performance. The method presented here allows the automatic generation of valves similar to the Tesla one, obtained automatically by a topology optimization algorithm. It is the first time that a three dimensional method is presented, the available algorithms in the open literature works in two dimensions. A fluid sedimentation process enables the creation of a new geometry optimized to meet a prescribed set of performance, such as pressure losses. The steepest descent method is used to approximate the integrals met during the calculation process. The optimizer is used to obtain three dimensional geometries for different multi-objective functions. The geometry is compared to an existing similar solution proposed in the open literature and validated. The results are compared to a Tesla valve to show the performance of the optimized geometries. The advantage of the proposed solution is the possibility to apply the design method with any spatial constraints and for a wide range of mass flow.

scholarly journals Rapid and Blind Watermarking Approach of the 3D Objects Using QR Code Images for Securing Copyright

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hanan S. Al-Saadi ◽  
Ahmed Elhadad ◽  
A. Ghareeb
Keyword(s):  
Digital Media ◽  
Three Dimensional ◽  
Extraction Process ◽  
Manhattan Distance ◽  
Human Observer ◽  
Qr Code ◽  
3D Object ◽  
3D Objects ◽  
Wide Range ◽  
Code Image

Watermarking techniques in a wide range of digital media was utilized as a host cover to hide or embed a piece of information message in such a way that it is invisible to a human observer. This study aims to develop an enhanced rapid and blind method for producing a watermarked 3D object using QR code images with high imperceptibility and transparency. The proposed method is based on the spatial domain, and it starts with converting the 3D object triangles from the three-dimensional Cartesian coordinate system to the two-dimensional coordinates domain using the corresponding transformation matrix. Then, it applies a direct modification on the third vertex point of each triangle. Each triangle’s coordinates in the 3D object can be used to embed one pixel from the QR code image. In the extraction process, the QR code pixels can be successfully extracted without the need for the original image. The imperceptibly and the transparency performances of the proposed watermarking algorithm were evaluated using Euclidean distance, Manhattan distance, cosine distance, and the correlation distance values. The proposed method was tested under various filtering attacks, such as rotation, scaling, and translation. The proposed watermarking method improved the robustness and visibility of extracting the QR code image. The results reveal that the proposed watermarking method yields watermarked 3D objects with excellent execution time, imperceptibility, and robustness to common filtering attacks.

scholarly journals COMPUTER MODELING USING THE AUTODESK 3D STUDIO MAX EDITOR

2020 ◽  
Vol 69 (1) ◽  
pp. 440-444
Author(s):  
A.R. Turganbayeva ◽  
◽  
F.K. Bolysbekova ◽  
Keyword(s):  
High School Students ◽  
Computer Modeling ◽  
Three Dimensional ◽  
3D Models ◽  
Third Party ◽  
School Students ◽  
3D Objects ◽  
3D Data ◽  
Wide Range ◽  
Cross Platform

This article describes in detail the capabilities of the Autodesk 3D Studio Max editor, which allows secondary school students to master three-dimensional computer modeling. To do this, we selected and studied modeling methods that allow us to create models of various complexity. The article provides modules and operators that can create part models and create real-world effects, create relationships between parts, and combine parts with each other and other objects. We studied the well-known visualization tools for working with three-dimensional graphics Autodesk 3D Studio Max. As a result of the experiment, it was proved that this platform is popular due to a wide range of features that facilitate the creation of complex 3D objects and scenes. It turned out that the Autodesk FBX cross-platform was designed to create 3D data and share it. It provides access to 3D models created in most third-party systems. Conclusions were made that it is available for high school students to master.

scholarly journals Micro- and Macro-Scale Measurement of Flow Velocity in Porous Media: A Shadow Imaging Approach for 2D and 3D

Optics ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Reza Sabbagh ◽  
Mohammad Amin Kazemi ◽  
Hirad Soltani ◽  
David S. Nobes
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Flow Pattern ◽  
Flow Measurement ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Detailed Knowledge ◽  
Micro Scale ◽  
Macro Scale

Flow measurement in porous media is a challenging subject, especially when it comes to performing a three-dimensional (3D) velocimetry at the micro scale. Volumetric flow measurement techniques such as defocusing and tomographic imaging generally involve rigorous procedures, complex experimental setups, and multi-part data processing procedures. However, detailed knowledge of the flow pattern at the pore and subpore scales is important in interpreting the phenomena that occur inside the porous media and understanding the macro-scale behaviors. In this work, the flow of an oil inside a porous medium is measured at the pore and subpore scales using refractive index matching (RIM) and shadowgraph imaging techniques. At the macro scale, flow is measured using the particle image velocimetry (PIV) method in two dimensions (2D) to confirm the volumetric nature of the flow and obtain the overall flow pattern in the vicinity of the flow entrance and at the far field. At the micro scale, the three-dimensional (3D) flow within an arbitrary volume of the porous medium was quantified using 2D particle-tracking velocimetry (PTV) utilizing the law of conservation of mass. Using the shadowgraphy method and a single camera makes the flow measurement much less complex than the approaches using laser light sheets or multiple cameras with multiple viewing angles.

Three-dimensional sub-wavelength fabrication by integration of additive and subtractive femtosecond-laser direct writing

2013 ◽  
Vol 1499 ◽  
Author(s):  
Wei Xiong ◽  
Yunshen Zhou ◽  
Xiangnan He ◽  
Yang Gao ◽  
Masoud Mahjouri-Samani ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Three Dimensional ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Nano Fabrication ◽  
Two Photon ◽  
Micro Fluidics ◽  
Wide Range ◽  
Device Structures ◽  
Two Photon Polymerization

ABSTRACTAdditive nanofabrication by two-photon polymerization (TPP) has recently drawn increased attention due to its sub-100 nm resolution and truly three-dimensional (3D) structuring capability. However, besides additive processes, subtractive process is also demanded for many 3D fabrications. Method possessing both additive and subtractive fabrication capabilities was rarely reported. In this study, we developed a complementary 3D micro/nano-fabrication process by integrating both additive two-photon polymerization (TPP) and subtractive multi-photon ablation (MPA) into a single platform of femtosecond-laser direct writing process. Functional device structures were successfully fabricated including: polymer fiber Bragg gratings containing periodic holes of 500-nm diameter and 3D micro-fluidic systems containing arrays of channels of 1-µm diameter. The integration of TPP and MPA processes enhances the nanofabrication efficiency and enables the fabrication of complex 3D micro/nano-structures that are impractical to produce by either TPP or MPA alone, which is promising for a wide range of applications including integrated optics, metamaterials, MEMS, and micro-fluidics.

scholarly journals Acoustic hologram optimisation using automatic differentiation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tatsuki Fushimi ◽  
Kenta Yamamoto ◽  
Yoichi Ochiai
Keyword(s):  
Phase Modulation ◽  
Automatic Differentiation ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Phase Plate ◽  
Signal Ratio ◽  
Wide Range ◽  
Output Amplitude ◽  
Optimisation Methods ◽  
Conventional Algorithm

AbstractAcoustic holograms are the keystone of modern acoustics. They encode three-dimensional acoustic fields in two dimensions, and their quality determines the performance of acoustic systems. Optimisation methods that control only the phase of an acoustic wave are considered inferior to methods that control both the amplitude and phase of the wave. In this paper, we present Diff-PAT, an acoustic hologram optimisation platform with automatic differentiation. We show that in the most fundamental case of optimizing the output amplitude to match the target amplitude; our method with only phase modulation achieves better performance than conventional algorithm with both amplitude and phase modulation. The performance of Diff-PAT was evaluated by randomly generating 1000 sets of up to 32 control points for single-sided arrays and single-axis arrays. This optimisation platform for acoustic hologram can be used in a wide range of applications of PATs without introducing any changes to existing systems that control the PATs. In addition, we applied Diff-PAT to a phase plate and achieved an increase of > 8 dB in the peak noise-to-signal ratio of the acoustic hologram.

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