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In fabricating functional layers, including thin-film transistors and conductive electrodes, using roll-to-roll (R2R) processing on polymer-based PET film, the instability of the slot-die coating meniscus under a high-speed web impedes functional layer formation with the desired thickness and width. The thickness profiles of the functional layers significantly impact the performance of the final products. In this study, we introduce an electrohydrodynamic (EHD)-based voltage application module to a slot-die coater to ensure the uniformity of the cross-machine direction (CMD) thickness profile within the functional layer and enable a stable, high-speed R2R process. The module can effectively control the spreadability of the meniscus by utilizing variations in the surface tension of the ink. The effectiveness of the EHD module was experimentally verified by applying a high voltage to a slot-die coater while keeping other process variables constant. As the applied voltage increases, the CMD thickness deviation reduces by 64.5%, and the production rate significantly increases (up to 300%), owing to the formation of a stable coated layer. The introduction of the EHD-based application module to the slot-die coater effectively controlled the spreadability of the meniscus, producing large-area functional layers. [ABSTRACT FROM AUTHOR]

Thickness nonuniformity is a bottleneck in the micro electroforming process of micro-metal devices. In this paper, a new method of fabricating a layered auxiliary cathode is proposed to improve the thickness uniformity of a micro-electroforming layer. In order to analyze the general applicability of the proposed method, four basic microstructures, namely circular, square, regular triangular, and regular hexagonal were used to study the effect of a layered auxiliary cathode on thickness uniformity through simulation and experimentation. The simulation results showed that with the help of the proposed auxiliary cathode, the thickness nonuniformity of four microstructures should decrease due to the reduced edge effect of the current density. The experimental results showed that the thickness uniformity of four microstructures fabricated via the proposed method was improved by 190.63%, 116.74%, 80.43%, and 164.30% compared to that fabricated via the traditional method, respectively. Meanwhile, the micro-gear was fabricated and the nonuniformity was reduced by 101.15% using the proposed method. [ABSTRACT FROM AUTHOR]

In order to improve the thickness uniformity of the electroformed metal layer and components, a new electroforming technique is proposed—wire-anode scanning electroforming (WAS-EF). WAS-EF uses an ultrafine inert anode so that the interelectrode voltage/current is superimposed upon a very narrow ribbon-shaped area at the cathode, thus ensuring better localization of the electric field. The anode of WAS-EF is in constant motion, which reduces the effect of the current edge effect. The stirring paddle of WAS-EF can affect the fluid flow in the microstructure, and improve the mass transfer effect inside the structure. The simulation results show that, when the depth-to-width ratio decreases from 1 to 0.23, the depth of fluid flow in the microstructure can increase from 30% to 100%. Experimental results show that. Compared with the traditional electroforming method, the single metal feature and arrayed metal components prepared by WAS-EF are respectively improved by 15.5% and 11.4%. [ABSTRACT FROM AUTHOR]

The thickness nonuniformity of an electroformed layer is a bottleneck problem for electroformed micro metal devices. In this paper, a new fabrication method is proposed to improve the thickness uniformity of micro gear, which is the key element of various microdevices. The effect of the thickness of the photoresist on the uniformity was studied by simulation analysis, which showed that as the thickness of the photoresist increased, the thickness nonuniformity of the electroformed gear should decrease due to the reduced edge effect of the current density. Differently from the traditional method performed by one-step front lithography and electroforming, multi-step, self-aligned lithography and electroforming are used to fabricate micro gear structures in proposed method, which intermittently keeps the thickness of photoresist from decreasing during processes of alternate lithography and electroforming. The experimental results show that the thickness uniformity of micro gear fabricated by the proposed method was improved by 45.7% compared with that fabricated by the traditional method. Meanwhile, the roughness of the middle region of the gear structure was reduced by 17.4%. [ABSTRACT FROM AUTHOR]

Uniform wall thickness plays an essential role in avoiding forming failure in incremental sheet forming. However, it is challenging to promote the uniform distribution of wall thickness in single-pass forming of high wall angle and complex three-dimensional thin-walled parts using flexible dieless incremental sheet forming technology. In this article, based on the hydraulic support single-point incremental sheet forming technology, the finite element software is used to simulate and analyze the influence of different support pressure on the wall thickness distribution and the uniform critical angle of single-pass incremental sheet forming truncated pyramid parts. The results show that the hydraulic support can effectively improve the thickness uniformity and critical forming angle. In addition, a single-point increment experiment system of hydraulic support is designed, and the uniform critical angle of wall thickness corresponding to different support pressure is obtained. The experimental results are consistent with the finite element simulation results. Therefore, this article provides guidance for manufacturing high wall angles and complex parts with uniform wall thickness in single-pass incremental sheet forming. [ABSTRACT FROM AUTHOR]

Abstract Background To evaluate the surface quality and thickness uniformity of lamellar donor grafts using an optional surgical technique called reversed manual dissection (RMD) in porcine corneas. Methods Twenty-four paired porcine corneas (48 eyes) were numbered 1 to 24 and divided into 6 groups. All left corneas were assigned to conventional manual dissection (CMD), and all right corneas were assigned to RMD. Each group contained 8 corneas. For Groups I, II, and III, 30, 50, and 70% of the entire corneal thickness was dissected using CMD. For groups IV, V, and VI, 70, 50, and 30% of the entire corneal thickness was dissected using RMD. The residual stromal thickness was examined by anterior segment optical coherence tomography (ASOCT) to assess the thickness uniformity and scanning electron microscopy (SEM) to assess the surface quality. Results The thickness uniformity of the lamellar grafts between each paired group was not significantly different (p > 0.05). The qualitative surface roughness grading (QiSR) evaluated by masked observers through SEM was significantly higher in the RMD groups (p

Thickness nonuniformity is a bottleneck in the micro electroforming process of micro-metal devices. In this paper, a new method of fabricating a layered auxiliary cathode is proposed to improve the thickness uniformity of a micro-electroforming layer. In order to analyze the general applicability of the proposed method, four basic microstructures, namely circular, square, regular triangular, and regular hexagonal were used to study the effect of a layered auxiliary cathode on thickness uniformity through simulation and experimentation. The simulation results showed that with the help of the proposed auxiliary cathode, the thickness nonuniformity of four microstructures should decrease due to the reduced edge effect of the current density. The experimental results showed that the thickness uniformity of four microstructures fabricated via the proposed method was improved by 190.63%, 116.74%, 80.43%, and 164.30% compared to that fabricated via the traditional method, respectively. Meanwhile, the micro-gear was fabricated and the nonuniformity was reduced by 101.15% using the proposed method.

Boron as thin film material is of relevance for use in modern micro- and nano-fabrication technology. In this research boron thin films are realized by a number of physical and chemical deposition methods, including magnetron sputtering, electron-beam evaporation, plasma enhanced chemical vapor deposition (CVD), thermal/non-plasma CVD, remote plasma CVD and atmospheric pressure CVD. Various physical, mechanical and chemical characteristics of these boron thin films are investigated, i.e., deposition rate, uniformity, roughness, stress, composition, defectivity and chemical resistance. Boron films realized by plasma enhanced chemical vapor deposition (PECVD) are found to be inert for conventional wet chemical etchants and have the lowest amount of defects, which makes this the best candidate to be integrated into the micro-fabrication processes. By varying the deposition parameters in the PECVD process, the influences of plasma power, pressure and precursor inflow on the deposition rate and intrinsic stress are further explored. Utilization of PECVD boron films as hard mask for wet etching is demonstrated by means of patterning followed by selective structuring of the silicon substrate, which shows that PECVD boron thin films can be successfully applied for micro-fabrication. [ABSTRACT FROM AUTHOR]

Background: To evaluate the surface quality and thickness uniformity of lamellar donor grafts using an optional surgical technique called reversed manual dissection (RMD) in porcine corneas.Methods: Twenty-four paired porcine corneas (48 eyes) were numbered 1 to 24 and divided into 6 groups. All left corneas were assigned to conventional manual dissection (CMD), and all right corneas were assigned to RMD. Each group contained 8 corneas. For Groups I, II, and III, 30, 50, and 70% of the entire corneal thickness was dissected using CMD. For groups IV, V, and VI, 70, 50, and 30% of the entire corneal thickness was dissected using RMD. The residual stromal thickness was examined by anterior segment optical coherence tomography (ASOCT) to assess the thickness uniformity and scanning electron microscopy (SEM) to assess the surface quality.Results: The thickness uniformity of the lamellar grafts between each paired group was not significantly different (p > 0.05). The qualitative surface roughness grading (QiSR) evaluated by masked observers through SEM was significantly higher in the RMD groups (p < 0.001). The quantitative surface roughness grading (QnSR) acquired from the Mountains software was significantly lower in the RMD groups (p < 0.001).Conclusions: RMD is an optional surgical technique for obtaining porcine lamellar grafts. The thickness uniformity of RMD is comparable to that of CMD, and a smoother surface with fewer ridges and roughness is achieved compared to CMD. [ABSTRACT FROM AUTHOR]

In order to improve the thickness uniformity of the electroformed metal layer and components, a new electroforming technique is proposed—wire-anode scanning electroforming (WAS-EF). WAS-EF uses an ultrafine inert anode so that the interelectrode voltage/current is superimposed upon a very narrow ribbon-shaped area at the cathode, thus ensuring better localization of the electric field. The anode of WAS-EF is in constant motion, which reduces the effect of the current edge effect. The stirring paddle of WAS-EF can affect the fluid flow in the microstructure, and improve the mass transfer effect inside the structure. The simulation results show that, when the depth-to-width ratio decreases from 1 to 0.23, the depth of fluid flow in the microstructure can increase from 30% to 100%. Experimental results show that. Compared with the traditional electroforming method, the single metal feature and arrayed metal components prepared by WAS-EF are respectively improved by 15.5% and 11.4%.

Uniform wall thickness plays an essential role in avoiding forming failure in incremental sheet forming. However, it is challenging to promote the uniform distribution of wall thickness in single-pass forming of high wall angle and complex three-dimensional thin-walled parts using flexible dieless incremental sheet forming technology. In this article, based on the hydraulic support single-point incremental sheet forming technology, the finite element software is used to simulate and analyze the influence of different support pressure on the wall thickness distribution and the uniform critical angle of single-pass incremental sheet forming truncated pyramid parts. The results show that the hydraulic support can effectively improve the thickness uniformity and critical forming angle. In addition, a single-point increment experiment system of hydraulic support is designed, and the uniform critical angle of wall thickness corresponding to different support pressure is obtained. The experimental results are consistent with the finite element simulation results. Therefore, this article provides guidance for manufacturing high wall angles and complex parts with uniform wall thickness in single-pass incremental sheet forming.

The thickness nonuniformity of an electroformed layer is a bottleneck problem for electroformed micro metal devices. In this paper, a new fabrication method is proposed to improve the thickness uniformity of micro gear, which is the key element of various microdevices. The effect of the thickness of the photoresist on the uniformity was studied by simulation analysis, which showed that as the thickness of the photoresist increased, the thickness nonuniformity of the electroformed gear should decrease due to the reduced edge effect of the current density. Differently from the traditional method performed by one-step front lithography and electroforming, multi-step, self-aligned lithography and electroforming are used to fabricate micro gear structures in proposed method, which intermittently keeps the thickness of photoresist from decreasing during processes of alternate lithography and electroforming. The experimental results show that the thickness uniformity of micro gear fabricated by the proposed method was improved by 45.7% compared with that fabricated by the traditional method. Meanwhile, the roughness of the middle region of the gear structure was reduced by 17.4%.

Smooth surface morphology and high thickness uniformity heteroepitaxy of corundum-structured (α-) gallium oxide (Ga 2 O 3) crystalline thin films on 100-mm diameter c -plane sapphire substrates were successfully demonstrated using vertical hot-wall mist chemical vapor deposition (CVD). The growth rate and surface morphology of the epitaxial layers were numerically and experimentally found to be dependent on the diameter of the precursor-diluted microdroplets approaching the substrate surface. Since the microdroplet is gradually evaporated while traveling through the furnace, the growth variables such as temperature, mist-flow velocity, and substrate position were tuned to obtain a suitable diameter of microdroplets approaching the substrate. In this study, the diameter of the approaching microdroplet was ≈2 μm, which was optimal for the smooth surface (root mean square roughness ≈1 nm) of α -Ga 2 O 3 epitaxial layers with a growth rate of ≈230 nm/h. Due to the even flow of mist in the vertical furnace, high thickness uniformity of the α -Ga 2 O 3 epitaxial layer is guaranteed on large-scale substrates, with a standard deviation of thickness as small as 28 nm, paving the way for highly reliable Ga 2 O 3 -based electric and optoelectronic devices. [ABSTRACT FROM AUTHOR]

To improve the thickness uniformity of sheet metal parts in incremental forming method based on a virtual auxiliary body, the effect of relevant parameters on the thickness uniformity was studied from both overall and local perspectives. Finite element (FE) method was used to carry out the single-factor and two-level factorial experiments, in which standard deviation of the thickness of section nodes was used as a response to analyzing the effect of factors on the thickness uniformity. First, the mean effects of each factor were obtained and the factor levels of factorial experiments were determined through a single-factor experiment. Then, the interaction effect between factors was analyzed and the optimal combination of parameters was determined through factorial experiments. From the FE analysis, it was found that the desired forming angle and the gap at the bottom have obvious mean effects and interactional effects on the thickness uniformity. Finally, the initial and optimal parameters were used for forming experiments. In the forming experiments, the overall and local thickness standard deviations of section nodes were reduced from 0.194 to 0.088 mm and from 0.149 to 0.081 mm, respectively, which means that the optimized parameters can effectively improve the thickness uniformity of sheet metal parts. [ABSTRACT FROM AUTHOR]

Featured Application: This paper presents a stretching process of a metal sheet with a variable thickness. It gives products with better performances than that with constant thickness. This work presents a finite element model to analyze the distribution of the strains due to an axisymmetric stretching of a metal sheet. The sheet is characterized by a variable initial thickness. The resulting strain state is compared with that of a sheet with a constant initial thickness. The results of the present study allow asserting that the distribution of strains in the sheet can be controlled by setting opportunely the trend of the sheet initial thickness. In this way, it is possible to see that, starting from a sheet with variable initial thickness, a lighter final product is obtained, whose final thickness distribution is more uniform than that of the product obtained from a classic stretching process that requires a sheet with constant initial thickness. Encouraging results from an experimental activity carried out on an AA6060 aluminum alloy sheet, whose trend of initial thicknesses was prepared by removing material from a commercial sheet with a constant thickness, allow us to note the good agreement with what was theoretically highlighted. [ABSTRACT FROM AUTHOR]

In all animals, the hide mass increases together with live body weight. At the age of 6 months and 3 years, the total weight of yak hide is almost two times higher than in other cattle. At 6 months, the thickness of yak hide in all topographical points exceeds that of cowhide by almost two times. By one and three years, the difference in the reference point disappears. However, the neck and the bellous hides of yak remain 25–40% thicker, and the skin area of other breeds of cattle exceeds that of yak at all ages by 35–40%. For the yaks of the Aininks Region, the optimal hide removal period is from birth to 3–4 years. For the animals over 4 years old, the hide yield by weight becomes relatively low. As far as thickness uniformity is concerned, the best skins for leather processing are those obtained from yaks under 3 years old, since they have the lowest degree of slackness. As for the chemical composition, the moisture of yak hide is 2.0–2.5% higher and the hide substance is 7.0–18.5% lower than in cowhide. This is, probably, connected with a certain reserve of water, or the so-called «depot moisture», in the skin of the animal. For all age periods, the moisture of the bellous yak hides is lower and fat content is by 1.5–2.2% higher than in other topographical areas. Apparently, this is due to the thermal adaptation of animals to the habitat conditions.

We herein report the effect of the viscosity of a prepolymer solution on the thickness uniformity of silver-nanowire-embedded flexible transparent electrodes. We adopted a model system with all the prepolymer solutions possessing identical physical properties except for the viscosity and then explored the most common prepolymer solutions for silver-nanowire-embedded flexible electrodes. In all experiments, single-step spin coating was conducted to coat the prepolymer solution on silver nanowires. We found that the electrodes were thinner for lower viscosity. However, the thickness ratio between the center and edge was comparable (50–60%) and independent of the prepolymer solution viscosity. This indicates that the viscosity does not determine the thickness uniformity, and that the coating method itself is vital to obtain films with uniform thickness. The flexible electrodes were introduced into organic solar cells. Their device performance was comparable regardless of the position of the electrodes and their thickness. This is because the thickness difference of the flexible electrodes did not affect their transmittance significantly. Thus, we conclude that although different coating approaches are needed to obtain flexible electrodes with high uniformity, the performance of optoelectronic devices on silver-nanowire-embedded flexible electrodes is independent of them. [ABSTRACT FROM AUTHOR]

This work presents a finite element model to analyze the distribution of the strains due to an axisymmetric stretching of a metal sheet. The sheet is characterized by a variable initial thickness. The resulting strain state is compared with that of a sheet with a constant initial thickness. The results of the present study allow asserting that the distribution of strains in the sheet can be controlled by setting opportunely the trend of the sheet initial thickness. In this way, it is possible to see that, starting from a sheet with variable initial thickness, a lighter final product is obtained, whose final thickness distribution is more uniform than that of the product obtained from a classic stretching process that requires a sheet with constant initial thickness. Encouraging results from an experimental activity carried out on an AA6060 aluminum alloy sheet, whose trend of initial thicknesses was prepared by removing material from a commercial sheet with a constant thickness, allow us to note the good agreement with what was theoretically highlighted.

Highlights • Effect of substrate surface roughness on thickness uniformity of complex GLC coatings was studied. • Thickness uniformity of GLC coating was improved by the introduction of element Y. • The number of elements Y, Ce and Ta inserts were optimized to obtain uniform thickness distribution. • Vibration attenuation was obtained by depositing uniform complex GLC coating on the gear. Abstract In this paper, the effects of substrate surface roughness and the addition of yttrium, cerium and tantalum on thickness uniformity of graphite-like carbon (GLC) coatings on gears were studied by magnetron sputtering method using mosaic targets. And noise reduction effects of gear pump deposited with complex GLC coatings were evaluated at different rotate speeds. The results showed that target-substrate distance, sputtering angle and surface roughness had influences on thickness uniformity of GLC coatings on gear. The introduction of elements Y, Ce and Ta into GLC coatings could effectively improve their thickness uniformity. The complex GLC coating with optimal thickness uniformity on gear exhibited significantly reduction effect for gear noise and the reduction effect for axial vibration was better than that of radial vibrations. Compared with uncoated gears, the noise for the coated gears was decreased by 10 dB at 2000 rpm. Good high-frequency noise reduction was obtained, which could be decreased by 19 dB in the range of 4000–10,000 Hz. [ABSTRACT FROM AUTHOR]

We herein report the effect of the viscosity of a prepolymer solution on the thickness uniformity of silver-nanowire-embedded flexible transparent electrodes. We adopted a model system with all the prepolymer solutions possessing identical physical properties except for the viscosity and then explored the most common prepolymer solutions for silver-nanowire-embedded flexible electrodes. In all experiments, single-step spin coating was conducted to coat the prepolymer solution on silver nanowires. We found that the electrodes were thinner for lower viscosity. However, the thickness ratio between the center and edge was comparable (50−60%) and independent of the prepolymer solution viscosity. This indicates that the viscosity does not determine the thickness uniformity, and that the coating method itself is vital to obtain films with uniform thickness. The flexible electrodes were introduced into organic solar cells. Their device performance was comparable regardless of the position of the electrodes and their thickness. This is because the thickness difference of the flexible electrodes did not affect their transmittance significantly. Thus, we conclude that although different coating approaches are needed to obtain flexible electrodes with high uniformity, the performance of optoelectronic devices on silver-nanowire-embedded flexible electrodes is independent of them.

The spray painting robots with mounted electrostatic rotating bell (ESRB) atomizers have been widely used to maintain high painting quality for various car models in rapid automotive production. The focus of this study is on developing the optimum coating path pitch while considering automobile painting quality. We define a deposition model optimized for the ESRB atomizer and introduce a method to optimize the path pitch with a cost function for painting thickness uniformity, which plays an important role in painting quality. In addition, experimental results are presented to verify the validity of the optimal path pitch simulation results. By using the results of this study, it is possible to improve the painting quality and thus the productivity of spray painting robots. [ABSTRACT FROM AUTHOR]

This study examines the solution for one of the most difficult problems of electroforming process “thickness deviation”. As an effective solution, an auxiliary electrode (dummy cathode) is considered. Generally, the thickness of an edge plating area is almost twice the center area or greater. An auxiliary electrode (intentionally attached dummy cathode) has helped to achieve more uniform thickness of the electroformed-nickel layer by preventing excessive electric charge. In addition, computer-aided analysis was performed to determine the optimal condition of electroforming process and to confirm the experimental result.

Nanotwinned (nt) Cu has received much attention because of its superior mechanical and electrical properties, but only a few production processes can yield nt-Cu parts with uniform thickness and a homogeneous microstructure on the wafer scale. To solve this problem, a new precision electroforming process is proposed that combines auxiliary cathodes with pulse reverse current (PRC) electroforming, which provides a synergistic effect to increase the homogeneity of the thickness and a nanoscale twin structure. As a practical example of the proposed process, 4-inch nt-Cu lamina arrays were fabricated and numerically modeled to probe into the synergistic mechanisms. The intrinsic correlations among the array element spacing, current waveform, and main forms of thickness nonuniformity were determined. In addition, the effects of the processing parameters on the microstructural evolution and microhardness of the nt-Cu arrays were analyzed. The results indicated that such a significant improvement in thickness uniformity and microstructure homogeneity were due to the auxiliary-cathode/PRC combination, which enables maximization of the PRC leveling efficiency by inducing a uniform current distribution; this effectively ensures that the microstructures are uniform across all laminae on the wafer scale. Additionally, thick nt-Cu deposited on the current-crowding regions was preferentially stripped during the application of reverse current. This alleviates the adverse effects of the current redistribution resulting from the auxiliary cathode on the thickness uniformity of the laminae and offers additional possibilities for homogeneous growth of nt-Cu. The new precision electroforming process has significant potential to produce wafer-scale components with uniform thickness and specific microstructures. [Display omitted] • A new precision electroforming process based on the combination of auxiliary cathode and pulse reverse current is proposed. • The process can fabricate wafer-scale array components with uniform thickness and homogeneous microstructures. • Numerical simulation and experimental studies highlighted the synergistic mechanisms controlling the thickness and microstructure. • The process maximizes the leveling efficiency while minimizing the current-redistribution problems caused by the auxiliary cathode. • The relationship between processing parameters, thickness distribution, microstructure, and microhardness were established. [ABSTRACT FROM AUTHOR]

In order to overcome difficulties in non-uniform thickness distribution and cracking failure during rectangular tube quasi-static hydroforming, a new forming technology, named as electromagnetically assisted hydroforming, is put forward. Both experiment and finite element method were conducted to investigate corner deformability and deformation pattern and its effect mechanisms. Results indicate that both corner deformability and thickness distribution are improved greatly under electromagnetic-assisted hydroforming. The reason is that deformation behavior changed after electromagnetic force application. As electromagnetic force is applied, tine petal cross sections are periodically produced and flattened. Thus, petal-like preform continues to generate and play a useful role in corner filling. Such deformation pattern overcomes friction holding back defect and results in stress state going over from tensile stress to compressive stress, which helps to avoid cracking failure and greatly improve thickness uniformity. At the same time, it also contributes to improve surface quality and decrease forming pressure simultaneously. [ABSTRACT FROM AUTHOR]

This study examines the solution for one of the most difficult problems of electroforming process “thickness deviation”. As an effective solution, an auxiliary electrode (dummy cathode) is considered. Generally, the thickness of an edge plating area is almost twice the center area or greater. An auxiliary electrode (intentionally attached dummy cathode) has helped to achieve more uniform thickness of the electroformed-nickel layer by preventing excessive electric charge. In addition, computer-aided analysis was performed to determine the optimal condition of electroforming process and to confirm the experimental result. [ABSTRACT FROM AUTHOR]

Damaged eggshells result in losses of eggs. Numerous efforts have been carried out to improve eggshell quality, which may lead to increased eggshell thickness. The conventional way of enhancing eggshell strength with thicker eggshell on average may be replaced by a new strategy to improve eggshell uniformity without increasing eggshell thickness. To achieve this, it is necessary to investigate global variation of eggshell thickness. In this study, we used 100 fresh eggs from 52-wk-old layers of a commercial brown-egg variety. To determine the global variation of eggshell thickness, 42 points for each egg along both longitudinal and latitudinal axes were selected to measure thickness using an eggshell thickness gauge. The eggshell thickness from blunt to sharp end varied significantly (P < 0.05). The area surrounding the blunt end was the thinnest (0.341 ± 0.025 mm), whereas the area surrounding the sharp end was the thickest (0.367 ± 0.023 mm). It was found that the thickness of the sharp end was the closest to the average thickness of the whole eggshell and could be considered as a valid measurement of eggshell thickness. A new parameter, eggshell thickness uniformity, was defined as the reciprocal of the coefficient of variation (1/CV) of eggshell thickness from 42 points of each egg and can be used to evaluate the eggshell quality. Eggshell thickness uniformity was positively correlated with breaking strength (r = 0.341; P < 0.01), suggesting that the parameter may be used as a potential selection criterion in breeding program to improve eggshell quality without increasing eggshell thickness. [ABSTRACT FROM AUTHOR]

Abstract: The hydrogen-free diamond-like carbon (DLC) films are potential materials to be used as infrared anti-reflection protective coatings if their optical absorption can be reduced to get relatively thick films needed. In this study, hydrogen-free DLC films were deposited by the physical vapor deposition (PVD) method in an unbalanced magnetron sputtering (UBMS) system with a rectangle graphite target of 440×80 mm in the argon atmosphere. The UBMS system was described in detail and the magnetron field distribution of the target was denoted in this work. The film thickness uniformity was investigated and the results showed that this system is capable of depositing uniform films larger than 150 mm in diameter. The infrared transmission spectra of DLC films were analyzed by a FTIR spectrometer, the results indicating that transparent films were obtained in the infrared region for the single side DLC coated on the silicon and germanium substrates, and about 68.83% and 63.05% transmittance were achieved respectively at the wave number of 2983 /cm, close to theoretical value for non-absorption carbon material. No obvious absorption peaks were found between 5000 and 800 /cm. The refractive index and extinction coefficient of the DLC films deposited under optimized conditions were about 2.08 and 0.067 respectively at the wavelength of 1600 nm. These important optical characteristics showed that the hydrogen-free DLC films prepared in the UBMS system were suitable for infrared transmission enhancement applications. [Copyright &y& Elsevier]

One of the significant limitations of the pulsed laser deposition method in the mass-production-technologies of micro- and nanoelectronic and molecular device electronic fabrication is the issue of ensuring deposition of films with uniform thickness on substrates with large diameter (more than 100 mm) since the area of the laser spot (1–5 mm2) on the surface of the ablated target is incommensurably smaller than the substrate area. This paper reports the methodology that allows to calculate the distribution profile of the film thickness over the surface substrate with a large diameter, taking into account the construction and technological parameters of the pulsed laser deposition equipment. Experimental verification of the proposed methodology showed that the discrepancy with the experiment does not exceed 8%. The modeling of various technological parameters influence on the thickness uniformity has been carried out. Based on the modeling results, recommendations and parameters are proposed for manufacturing uniform thickness films. The results allow for increasing the film thickness uniformity with the thickness distribution < 5% accounts for ~ 31% of 300 mm diameter substrate. [ABSTRACT FROM AUTHOR]

• A concept of microfluidic valve is proposed for composite thickness uniformity control. • A self-adjusting elastomeric microfluidic valve is designed based on its self-structure of FRP composite. • The effectiveness of microfluidic valve is fully confirmed by real-time micro-flow monitoring. • The microfluidic valve exhibits self-adjusting, low-cost and easy-fabrication. Due to the existence of curvature, non-uniform pressure field forms within fiber reinforced polymer (FRP) composite during processing. Complex resin flow induces significant thickness deviation and defects concentration at corners. In this study, a microfluidic valve based on self-structure was proposed to restrict the mutual flow between regions for thickness uniformity control. Besides, little resin was actively guided to flow towards microfluidic valve, which helped avoid ply wrinkling, evacuate bubbles and enhance the surface quality of composite. By introducing an isolation film with a certain number of micropores on composite surface, the microfluidic valve formed naturally. Its microstructure adjusted self-adaptively to deviate local flow directions, and finally reverted to its initial states. This method allowed composite parts to be manufactured with uniform thickness (Maximum deviation of thickness: 0.01 mm), and without the need for extra hardware. [ABSTRACT FROM AUTHOR]

Incremental sheet forming (ISF) is a novel flexible forming technology with advantages, such as a low forming force, low-energy-consuming equipment, and good forming performance. The lack of available information about the formability of the two-point incremental forming (TPIF) process makes it limited for practical applications. Taking an irregular stepped part as the target part, the effects of process parameters on the thickness uniformity when using TPIF with a positive die for AA1060 aluminum alloy sheets were investigated. First, the set of optimal parameters regarding the diameter of the tool head, feed rate, and the step size were obtained through orthogonal experiments. Furthermore, the optimal parameter set of the number of forming passes, the direction of movement of the forming tool, and the forming angle was determined and the optimal forming result was numerically and experimentally verified. This demonstrated that the parameters affecting the thickness uniformity of the irregular stepped parts were, in descending order, the diameter of the forming tool, the feed rate, and the step size, with corresponding optimal values of 12 mm, 15,000 mm/min, and 0.4 mm, respectively. With an increase of the number of passes and a decrease of the forming angle between adjacent passes, and adopting an alternating clockwise and counterclockwise toolpath, the thickness uniformity of the formed parts was effectively improved. [ABSTRACT FROM AUTHOR]