scholarly journals A Comprehensive Review of Micro/Nano Precision Glass Molding Molds and Their Fabrication Methods

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 812
Author(s):  
Md. Ali Asgar ◽  
Jun Kim ◽  
Muhammad Refatul Haq ◽  
Taekyung Kim ◽  
Seok-min Kim
Keyword(s):  
Surface Roughness ◽  
Incident Light ◽  
Surface Finishing ◽  
Scattering Loss ◽  
Glass Molding ◽  
Glass Substrates ◽  
Precision Glass Molding ◽  
Wide Range ◽  
Mold Fabrication ◽  
Optical Applications

Micro/nano-precision glass molding (MNPGM) is an efficient approach for manufacturing micro/nanostructured glass components with intricate geometry and a high-quality optical finish. In MNPGM, the mold, which directly imprints the desired pattern on the glass substrate, is a key component. To date, a wide variety of mold inserts have been utilized in MNPGM. The aim of this article is to review the latest advances in molds for MNPGM and their fabrication methods. Surface finishing is specifically addressed because molded glass is usually intended for optical applications in which the surface roughness should be lower than the wavelength of incident light to avoid scattering loss. The use of molds for a wide range of molding temperatures is also discussed in detail. Finally, a series of tables summarizing the mold fabrication methods, mold patterns and their dimensions, anti-adhesion coatings, molding conditions, molding methods, surface roughness values, glass substrates and their glass transition temperatures, and associated applications are presented. This review is intended as a roadmap for those interested in the glass molding field.

Structrual Coloration of Surfaces With Microstructures Replicated by Non-Isothermal Precision Glass Molding

2020 ◽  
Author(s):  
Yong Zhong ◽  
Ruxu Du ◽  
Lin Zhang ◽  
Allen Y. Yi
Keyword(s):  
Periodic Structures ◽  
Low Cost ◽  
Incident Light ◽  
Molding Process ◽  
Glass Molding ◽  
Precision Glass Molding ◽  
Structural Colors ◽  
Periodic Grating ◽  
Light Beams ◽  
Micro Structures

Abstract Micro/nano periodic structures are generally adopted in diffraction gratings. As an important optical component, the diffraction grating has the capability to split and diffract incident white light beams into iridescent beams travelling in different directions. The emerging coloration is a form of structural coloration. In this paper, the non-isothermal precision glass molding is introduced for fast replication of periodic grating structures, which are employed to render iridescent colors on surfaces. Firstly, the effect of colorization and periodic grating profiles is theoretically analyzed. Secondly, different periodic micro gratings on silicon wafer, which are generally generated by photolithography, are employed in non-isothermal precision glass molding process as mold inserts. The molding result indicates that the periodic grating space and depth of grating structures can be precisely replicated from the mold inserts to polymer substrates. Subsequently, the split and iridescent color effects are demonstrated with monochromatic & white incident light beam and compared between samples with different periodic grating spaces. The optical effects of the replicated micro-structures confirm the feasibility of this method. The proposed non-isothermal precision glass molding process provides an alternative manufacturing option for realizing structural colors with large-volume and low-cost.

scholarly journals Improving the surface quality and mechanical properties of selective laser sintered PA2200 components by the vibratory surface finishing process

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Hamaid M. Khan ◽  
Tolga B. Sirin ◽  
Gurkan Tarakci ◽  
Mustafa E. Bulduk ◽  
Mert Coskun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Microstructural Analysis ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Surface Finishing ◽  
Finishing Process ◽  
Wide Range

Abstract This paper attempts to improve the physical and mechanical properties of selective laser sintered polyamide PA2200 components through a vibratory surface finishing process by inducing severe plastic deformation at the outer surface layers. The industrial target of additive manufacturing components is to obtain structures having surface roughness, hardness, and other mechanical properties equivalent to or better than those produced conventionally. Compared to the as-built SLS PA2200 samples, vibratory surface finishing treated specimens exhibited a smooth surface microstructure and more favorable roughness, hardness, and tensile strength. Also, the duration of the vibratory surface finishing process showed a further improvement in the surface roughness and hardness of the SLS samples. Compared to the as-built state, the roughness and hardness of the surface-treated samples improved by almost 90% and 15%, respectively. Consequently, microstructural analysis indicates that lower surface roughness and enhanced surface hardness is a crucial factor in influencing the overall tensile strength of SLS-PA2200 components. We consider that the combination of VSF and SLS processes can successfully handle a wide range of potential applications. This study also highlights the efficiency and applicability of the vibratory surface finishing process to other additive manufacturing processes and materials. Graphic abstract

Precision Glass Molding of High Filling Factor Micro Lens Arrays

2014 ◽  
Vol 939 ◽  
pp. 349-354
Author(s):  
Chun Chieh Chen ◽  
Chien Yao Huang ◽  
Wie Jei Peng ◽  
Wei Yao Hsu
Keyword(s):  
Surface Roughness ◽  
Filling Factor ◽  
Transmission Rate ◽  
Surface Generation ◽  
Generation Process ◽  
Mold Surface ◽  
Glass Molding ◽  
Precision Glass Molding ◽  
High Filling Factor ◽  
Micro Lens

Glass micro lens arrays (GMLAs) have several advantages such as a high transmission rate, anti-environment, and can be used for special wavelength applications. Precision glass molding (PGM) has been used to mass produce high-accuracy aspherical glass lenses. Ultra-precision diamond grinding (UPDG) is a fundamental part of the precision glass molding process. Using UPDG, grinding spherical and aspherical to sub-micrometer form and nanometer surface roughness is simple. However, asymmetrical surface MLAs are difficult to generate using the UPDG process. UPDG, together with the wheel-forming method and a strategy used to separate the entire surface generation process into several grinding loops, were studied and developed to generate high filling factor MLAs on the mold surface. The GMLA material used was K-CSK120, made by Sumita Inc., Japan. Finally, GMLAs with an approximately 100% filling factor were generated using PGM with form accuracy and surface roughness that were respectively less than 0.3 μm and 10 nm. The tolerance of each single micro lens figure was greater than 95%.

scholarly journals Controlling wave fronts with tunable disordered non-Hermitian multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denis V. Novitsky ◽  
Dmitry Lyakhov ◽  
Dominik Michels ◽  
Dmitrii Redka ◽  
Alexander A. Pavlov ◽  
...  
Keyword(s):  
Incident Light ◽  
Passage Time ◽  
Photonic Devices ◽  
Gain Saturation ◽  
Wave Fronts ◽  
Optical Effects ◽  
Front Shape ◽  
Optical Applications ◽  
Increasing Demand ◽  
First Time

AbstractUnique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and, therefore, providing a powerful tool to control both the passage time and the wave-front shape of incident light with different switching times. For the first time we show the possibility to switch on and off kink formation by changing the level of disorder in the case of adiabatically raising wave fronts. At the same time, we deliver flexible tuning of the output intensity by using the nonlinear effect of loss and gain saturation. Since the disorder strength in our system can be conveniently controlled with the power of the external pump, our approach can be considered as a basis for different active photonic devices.

Annealed high-phosphorus electroless Ni–P coatings for producing molds for precision glass molding

2021 ◽  
Vol 262 ◽  
pp. 124297
Author(s):  
Qian Yu ◽  
Tianfeng Zhou ◽  
Yupeng He ◽  
Peng Liu ◽  
Xibin Wang ◽  
...  
Keyword(s):  
Glass Molding ◽  
Precision Glass Molding ◽  
High Phosphorus ◽  
Electroless Ni

scholarly journals Nano-Crystallization of Ln-Fluoride Crystals in Glass-Ceramics via Inducing of Yb3+ for Efficient Near-Infrared Upconversion Luminescence of Tm3+

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1033
Author(s):  
Jianfeng Li ◽  
Yi Long ◽  
Qichao Zhao ◽  
Shupei Zheng ◽  
Zaijin Fang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
Upconversion Emission ◽  
Ceramic Composites ◽  
Wide Range ◽  
Transmission Window ◽  
Optical Applications ◽  
Upconversion Emissions

Transparent glass-ceramic composites embedded with Ln-fluoride nanocrystals are prepared in this work to enhance the upconversion luminescence of Tm3+. The crystalline phases, microstructures, and photoluminescence properties of samples are carefully investigated. KYb3F10 nanocrystals are proved to controllably precipitate in the glass-ceramics via the inducing of Yb3+ when the doping concentration varies from 0.5 to 1.5 mol%. Pure near-infrared upconversion emissions are observed and the emission intensities are enhanced in the glass-ceramics as compared to in the precursor glass due to the incorporation of Tm3+ into the KYb3F10 crystal structures via substitutions for Yb3+. Furthermore, KYb2F7 crystals are also nano-crystallized in the glass-ceramics when the Yb3+ concentration exceeds 2.0 mol%. The upconversion emission intensity of Tm3+ is further enhanced by seven times as Tm3+ enters the lattice sites of pure KYb2F7 nanocrystals. The designed glass ceramics provide efficient gain materials for optical applications in the biological transmission window. Moreover, the controllable nano-crystallization strategy induced by Yb3+ opens a new way for engineering a wide range of functional nanomaterials with effective incorporation of Ln3+ ions into fluoride crystal structures.

scholarly journals Bioinspired Living Coating System in Service: Evaluation of the Wood Protected with Biofinish during One-Year Natural Weathering

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 701
Author(s):  
Faksawat Poohphajai ◽  
Jakub Sandak ◽  
Michael Sailer ◽  
Lauri Rautkari ◽  
Tiina Belt ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Scots Pine ◽  
Critical Factor ◽  
Climatic Conditions ◽  
Natural Weathering ◽  
Surface Finishing ◽  
Attractive Alternative ◽  
Coating System ◽  
Self Healing ◽  
Wood Protection

The service life performance of timber products exposed to natural weathering is a critical factor limiting the broad use of wood as an external building element. The goal of this study was to investigate the in-service characterization of an innovative biofinish coating system. It is a novel surface finishing solution based on the bioinspired concept of living fungal cells designed for effective wood protection. The performance of Scots pine (Pinus sylvestris L.) wood coated with biofinish was compared with uncoated references. Samples were exposed to natural weathering for 12 months under the climatic conditions of northern Italy. The visual appearance, colour, gloss, wettability, and 3D surface topography of the wood surface were examined. Results revealed that the total colour changes (∆E) of biofinish-coated wood were negligible. Untreated Scots pine wood revealed the changes in colour after just three months of exposure. The gloss changes of both surface types were small. The contact angle measured on biofinish-coated wood was higher compared to that of uncoated Scots pine. Surface roughness increased in uncoated wood due to the erosion effect caused by the weathering progress. Conversely, the surface roughness of biofinish-coated samples decreased along the exposure time. This phenomenon was explained by two self-healing mechanisms: migration of non-polymerized oil to the cracked surface, where it polymerizes and creates a closed layer, and local regrowth to cover damaged spots by living fungal cells present in the coating. The obtained results revealed the superior aesthetic performance of the biofinish surface treatment against natural weathering. By considering the fully bio-based nature of the investigated coating, it was concluded that this solution can be an attractive alternative for state-of-the-art wood protection technologies.

Optical and Mechanical Properties of Aluminum Film Deposited on Glass Substrate

2010 ◽  
Vol 297-301 ◽  
pp. 444-449 ◽  
Author(s):  
Shiuh Chuan Her ◽  
Yi Hsia Wang
Keyword(s):  
Wavelength Region ◽  
Aluminum Film ◽  
Surface Topology ◽  
Aluminum Films ◽  
Glass Substrates ◽  
Atomic Force ◽  
Environmental Test ◽  
Optical Applications ◽  
Optical And Mechanical Properties ◽  
Al Thin Film

The aluminum film with high reflectivity and low absorption in the visible wavelength region has been widely used in optical applications. In this investigation, aluminum films were prepared on glass substrates by electron-beam vapor deposition. The reflectivity of the Al thin film was measured by a Perkin-Elmer Lambda spectrophotometer in the wavelength region of 450-680 nm. The experimental measurements of reflectivity were validated with the numerical results using the Essential Macleod software. The surface topology and microstructure of the film were examined by means of atomic force microscope (AFM). The effects of the temperature and humidity on the reflectivity of the Al film were examined by the environmental test. Nanoindentation tests were employed to determine the hardness and Young’s modulus of the film. The measured hardness of the Al thin films were found to depend on the penetration depth.

Analysis of Cu(InGa)Se2 Alloy Film Optical Properties and the Effect of Cu Off-Stoichiometry

2005 ◽  
Vol 865 ◽  
Author(s):  
P. D. Paulson ◽  
S. H. Stephens ◽  
W. N. Shafarman
Keyword(s):  
Optical Constants ◽  
Soda Lime ◽  
Alloy Film ◽  
Relative Volume ◽  
Soda Lime Glass ◽  
Distinctive Features ◽  
Glass Substrates ◽  
Wide Range ◽  
Two Phases

AbstractVariable angle spectroscopic ellipsometry has been used to characterize Cu(InGa)Se2 thin films as a function of relative Ga content and to study the effects of Cu off-stoichiometry. Uniform Cu(InGa)Se2 films were deposited on Mo-coated soda lime glass substrates by elemental evaporation with a wide range of relative Cu and Ga concentrations. Optical constants of Cu(InGa)Se2 were determined over the energy range of 0.75–C4.6 eV for films with 0 ≤ Ga/(In+Ga) ≤ 1 and used to determine electronic transition energies. Further, the changes in the optical constants and electronic transitions as a function of Cu off-stoichiometry were determined in Cu-In-Ga-Se films with Cu atomic concentration varying from 10 to 25 % and Ga/(In+Ga) = 0.3. Films with Cu in the range 16–24 % are expected to contain 2 phases so an effective medium approximation is used to model the data. This enables the relative volume fractions of the two phases, and hence composition, to be determined. Two distinctive features are observed in the optical spectra as the Cu concentration decreases. First, the fundamental bandgaps are shifted to higher energies. Second, the critical point features at higher energies become broader suggesting degradation of the crystalline quality of the material.

Sign in / Sign up

Export Citation Format

Share Document