Uniform Thickness Research Articles

Bonding-Directed Crystallization of Ultra-Long One-Dimensional NbS3 van der Waals Nanowires.

The rediscovery of one-dimensional (1D) and quasi-1D (q-1D) van der Waals (vdW) crystals ushered the realization of nascent physical properties in 1D that are suitable for applications in photonics, electronics, and sensing. However, despite renewed interest in the creation and understanding of the physical properties of 1D and q-1D vdW crystals, the lack of accessible synthetic pathways for growing well-defined nanostructures that extend across several length scales remains. Using the highly anisotropic 1D vdW NbS3-I crystal as a model phase, we present a catalyst-free and bottom-up synthetic approach to access ultralong nanowires, with lengths reaching up to 7.9 mm and with uniform thicknesses ranging from 13 to 160 nm between individual nanowires. Control over the synthetic parameters enabled the modulation of intra- and interchain growth modalities to selectively yield only 1D nanowires or quasi-2D nanoribbons. Comparative synthetic and density functional theory (DFT) studies with a closely related nondimerized phase, ZrS3, show that the unusual preferential growth along 1D can be correlated to the strongly anisotropic bonding and dimeric nature of NbS3-I.

Analysis of progress in research on technology for the detection and removal of foreign fibers

We focus in this review on the pre-processing devices used, the cotton pipeline, the rejection system, the acquisition and processing of information from images of raw cotton, and measurements of the rate of dynamic flow of the cotton stream. The results show that raw cotton fluffs into a material with a more uniform thickness, and adequately separating the cotton bunch can improve the subsequent detection and removal of foreign fibers in it. Moreover, research that combines the structure of the cotton pipeline with the optimization of the structure of the nozzle plate is important for improving the rejection of foreign fibers in cotton. Furthermore, a combination of multiple light sources and arrays of charge-coupled device cameras can improve the quality of images of raw cotton, but such key parameters as the power and wavelength of the source of light need to be optimized. As any single algorithm for image segmentation and feature extraction struggles to adapt to the identification of different kinds of foreign fibers, it is important to explore a combination of algorithms to this end, and to develop new techniques of foreign fiber detection based on deep learning. Finally, the structure and parameters of processing of the system for the identification and removal of foreign fibers are important, including the relative distance between the sensor and the nozzle, the width of the detection channel, and the rate of flow of the cotton stream.

Molecular dynamics study of the groove-forming mechanism of mechanically scratched grating multilayer aluminum films

For a long time, the forming quality of large area diffraction gratings is restricted by the one-time coating quality and uniformity of large thickness and large area aluminum films. Large thickness coatings, low accuracy of large depth grooves and diamond tool wear problems were the main reasons for the failure of the test to inscribe large area diffraction gratings. Therefore, the use of layered coating process can effectively ensure the uniformity and consistency of large-area and large-thickness grating blanks coated with aluminum film, and improve the high precision of large depth diffraction grating slot type. In order to reveal the mechanism of the groove-forming process of multilayer aluminum films, the microstructure and mechanical properties of different aluminum films were observed. In this article, the removal behavior and mechanism of nanomechanically scratched multilayer aluminum film materials are investigated using a molecular dynamics approach, and the characteristics of multilayer aluminum films scratched into grooves are analyzed in terms of surface morphology, scratching force, structural evolution, dislocation distribution, von Mises stress and shear strain. The results indicate that in the scratching simulation process, multilayer aluminum film has a higher number of removed atoms and a larger atomic displacement compared to single layer aluminum film, which is conducive to precise shape control of the groove. The average tangential force and normal force of multilayer aluminum film show a decreasing trend compared to single layer aluminum film, which helps to scratch grooves and reduce tool wear. The total length of the dislocation lines of the multilayer aluminum film is large, and the distribution area is large, which improves the precision of scratching the grooves. Therefore, an appropriate increase in the number of aluminum film layers has a precise control effect on the groove shape. This study has certain reference significance for analyzing the complex grooving deformation law of grating aluminum film, improving the diffraction efficiency of grating aluminum film, and further improving the manufacturing process of grating aluminum film.

Chitosan-based mucoadhesive films loaded with curcumin for topical treatment of oral cancer

This study aimed to develop mucoadhesive chitosan-based films capable of enhancing the curcumin penetration into the oral mucosa to treat oral cancers. We developed three films containing medium molecular weight chitosan (190–310 KDa) and other excipients (polyvinyl alcohol, Poloxamer®407, and propylene glycol) that have proven to be compatible with each other and with curcumin in thermal analyses. The films were smooth, flexible, and precipitates free, with uniform weight and thickness, pH compatible with the oral mucosa, resistance to traction, and entrapped curcumin in a high proportion. They also exhibited necessary swelling and mucoadhesion for tissue adherence. Ex vivo penetration studies proved that the films significantly increased the penetration of curcumin into the oral mucosa compared to control, even when the mucosa was subjected to a condition of simulated salivation. Curcumin exhibited cytotoxic activity in vitro in the two head and neck cancer cell lines (FaDu, SCC-9) at doses close to those found in penetration studies with the films. When combined with radiotherapy, curcumin demonstrated superiority over single doses of radiotherapy at 4, 8, and 12 Gy. Therefore, the developed films may represent a promising alternative for the topical treatment of oral tumors.

Study of Earthquake Landslide Hazard by Defining Potential Landslide Thickness Using Excess Topography: A Case Study of the 2014 Ludian Earthquake Area, China

Influenced by the combined effects of crustal uplift and river downcutting, rivers with significant potential energy are often found in high mountain and canyon areas. Due to the active tectonic movements that these areas have experienced or are currently experiencing, geological hazards frequently occur on the mountains flanking the rivers. Therefore, evaluating the susceptibility and risk of earthquake landslides in river segments of these high mountain and canyon areas is of great importance for disaster prevention and mitigation, as well as for the safe construction and operation of hydropower stations. Currently, a major challenge in the study of landslide susceptibility and hazard is determining the thickness of potential landslide bodies. The presence of excess topography reflects the instability of the disrupted slopes, which is also a fundamental cause of landslides. This study takes the example of the Ludian earthquake in 2014, focusing on the IX and VIII intensity zones, to extract the excess topography in the study area and analyze its correlation with seismic landslides. The correlation between the critical acceleration value and the excess topography was validated using the Spearman’s rank correlation coefficient, resulting in a correlation coefficient of −0.771. This indicates a strong negative correlation between the excess topography and critical acceleration, with significant relevance. The landslide susceptibility distribution obtained by setting the potential landslide thickness based on the excess topography and proportion coefficient showed an ROC curve analysis AUC value of 0.829. This is higher than the AUC value of 0.755 for the landslide susceptibility result using a uniform potential landslide thickness of 3 m, indicating the higher model evaluation accuracy of this approach. Earthquake landslide hazard predictions for rapid post-earthquake assessments and earthquake landslide hazard zoning for pre-earthquake planning were made using actual seismic ground motion and a 2% exceedance probability in 50 years, respectively. Comparing these with the 10,559 coseismic landslides triggered by the Ludian earthquake and evaluating the seismic landslide development rate, the results were found to be consistent with reality. The improved model better reflects the control of excess topography and rock mechanics properties on the development of earthquake landslide hazards on high steep slopes. Identifying high-risk seismic landslide areas through this method and taking corresponding preventive and protective measures can help plan and construct safer hydropower and other infrastructure, thereby enhancing their disaster resistance.

The concentration influence of multi-walled carbon nanotubes coating on fatigue edge crack growth and other mechanical properties of Al 7075-T6 thin plates

In the current study, the incline edge crack growth behavior in an aluminum alloy 7075-T6 specimens (which were coated using nickel-carbon nanotubes electroless coating) has been investigated undergoes uniaxial tensile fatigue loading. High purity multi walled carbon nanotubes have been used in nano-coating solutions with various concentrations (1 g/l, 2 g/l and 3 g/l) to examine the improvement extent of fatigue crack growth resistance and other mechanical properties. Water jet technique was used to cutting aluminum plates to the required dimensions before the nano-coating procedure. Multi-purpose fatigue apparatus has been adopted to apply tensile fatigue loading with zero stress ratios. High magnification camera with image j software has been utilized to measure the propagated crack lengths with the number of fatigue cycles. To inspection the quality, thickness uniformity and homogeneity of the nano-coating layer over specimen surfaces, EDXRF and FESEM techniques have been adopted in this study. Numerical simulation using ABAQUS 2021 programming was performed for the purpose of the results validation. The measured results offered a 25.9 %, 44.5 % and 47.9 % increasing in the hardness of the coated specimens using 1 g/l, 2 g/l and 3 g/l MWCNTs respectively. The modulus of elasticity produced an increasing of 26.7 %, 44.4 % and 46.3 % for the coated specimens using 1 g/l, 2 g/l and 3 g/l MWCNTs respectively. The nano-coating with 2 g/l MWCNTs produced more homogeneous, uniform thickness coating layer and fatigue crack growth resistance than that of the coated specimens using other concentrations of MWCNTs. The similarity in the crack growth behavior was the major outcome of the results validation from the fatigue tests and numerical simulation.

Evaluation of the Impact of Stress Distribution on Polyurethane Trileaflet Heart Valve Leaflets in the Open Configuration by Employing Numerical Simulation

It is costly and time-consuming to design and manufacture functional polyurethane heart valve prototypes, to evaluate and comprehend their hemodynamic behaviour. To enhance the rapid and effective design of replacement heart valves, to meet the minimum criteria of FDA and ISO regulations and specifications, and to reduce the length of required clinical testing, computational fluid dynamics (CFD) and finite element analysis (FEA) were used. The results revealed that when the flexibility of the stent was taken into consideration with a uniform leaflet thickness, stress concentration regions that were present close to the commissural attachment were greatly diminished. Furthermore, it was found that the stress on the leaflets was directly impacted by the effect of reducing the post height on both rigid and flexible stents. When varying the leaflet thickness was considered, the high-stress distribution close to the commissures appeared to reduce at thicker leaflet regions. However, thicker leaflets may result in a stiffer valve with a corresponding increase in pressure drop. It was concluded that a leaflet with predefined varying thickness may be a better option.

Numerical Analysis of Thickness Uniformity Improvement with Different Inlet Plate Numbers during APCVD Process

As the nanometer line width in the semiconductor industry further shrinks, the surface flatness requirements for atmospheric pressure chemical vapor deposition epitaxial silicon films have further increased. Through a series of numerical simulations, this study analyzes the use of inlet plates to solve the problem of uneven wafer thickness during atmospheric pressure chemical vapor deposition. The results show that without the inlet plate, the deposition rate is lower at the center of the wafer and higher at the edge of the wafer. Wafer epitaxy thickness uniformity can be improved when inlet plates are used. By adjusting the position of the inlet plates, this unevenness can be further improved. As the number of inlet plates increases from 0 to 3, the wafer thickness non-uniformity decreases from 12.5% to 1.8% respectively. When the number of inlet plates continues to increase, the thickness uniformity of the wafer can be further improved. When the number of inlet plates is 5, the thickness unevenness of the wafer reaches 0.7%.

Development of an advanced in-line multilayer deposition system at Diamond Light Source.

A state-of-the-art multilayer deposition system with a 4200 mm-long linear substrate translator housed within an ultra-high vacuum chamber has been developed. This instrument is engineered to produce single and multilayer coatings, accommodating mirrors up to 2000 mm in length through the utilization of eight rectangular cathodes. To ensure the quality and reliability of the coatings, the system incorporates various diagnostic tools for in situ thickness uniformity and stress measurement. Furthermore, the system features an annealing process capable of heating up to 700°C within the load-lock chamber. The entire operation, including pump down, deposition and venting processes, is automated through user-friendly software. In addition, all essential log data, power of sputtering source, working pressure and motion positions are automatically stored for comprehensive data analysis. Preliminary commissioning results demonstrate excellent lateral film thickness uniformity, achieving 0.26% along the translation direction over 1500 mm in dynamic mode. The multilayer deposition system is poised for use in fabricating periodic, lateral-graded and depth-graded multilayers, specifically catering to the beamlines for diverse scientific applications at Diamond Light Source.

The Influence of Calendering Process on the Graphite Anode

Calendering, or pressing, is the final property-defining process for battery electrode manufacturing to maximize the volumetric capacity of the cell through the compaction of an electrode between two large calender rollers12. On one hand, it can reduce the porosity of battery materials thus increase the conductivity of the materials. On the other hand, it can control the thickness of the electrodes, making sure it is uniform and proper thickness to guarantee the minimal variation in the cell thickness, reaching even stack pressure for module assembly and impacting the thermal management [3]. The calendering process significantly influence the performance of lithium-ion battery (LIB).Graphite anode coating on Cu foil was chosen as our baseline coating for this calendering process investigation. The slurry was mixed in a planetary and dispersive mixer and then coated using reverse comma coating method by a scale-up coater with drying zones of 70 °C. Then the coating was calendered by a calendering machine at various conditions.Calendering, though seemingly a simply process, is influenced by several different parameters significantly. In this study, we systematically investigated the calendering process by carrying-out a Design-of-experiment (DOE). The following calendering parameters were investigated: the parameters of calendering machine gap size, calendering pressure, and the speed of the coating web. The calendered graphite coating was then measured for the morphology by scanning electron microscopy (SEM), the pore size change by BET surface area measurement, and Direct current internal resistance (DCIR) by building half cells and cycling and Electrochemical Impedance Spectroscopy (EIS) at 50% State-of-Charge (SOC).The result showed that pressure is the most critical parameter for calendering and the internal resistance and ionic conductivity changes in response to the calendering parameters. The half-cell with calendering at the pressure of 37 MPa, gap size targeted for 30% porosity, the BET surface area around 0.75 m2/g showed highest cell capacity and lowest internal resistance.

Development of Efficient Ink Dispersion Process for Solid-State Electrolyte and Electrode Manufacturing

All-solid-state lithium batteries (ASSBs) have several advantages over lithium-ion batteries (LIBs) such as higher safety thresholds associated with solid electrolytes (SEs) and the possibility of using lithium metal or silicon anodes to achieve comparatively higher energy and power density. The SE can also prevent chemical interactions with dissolved active materials, and thus solve the issue of long-term instability of LIBs. However, there are also challenges associated with ASSBs manufacturing, such as local stress and contact-loss between SE and active materials in cathodes due to active material “breath”, poor contact and high ionic resistance at the SE-cathode interface, difficulty in fabricating thin SEs, and the absence of scalable and cost-effective manufacturing processes (J. Janek and W.G. Zeier, Nature Energy 8 (2023): 230-240). A key to tackling these issues begins with ink formulation for electrolyte and cathode coating, including ink compositions and rheological properties.In this study, we report the influence of ink preparation methods and conditions on the solid-state electrolyte and cathode coating qualities, where lithium lanthanum zirconium oxide (LLZO) and lithium nickel manganese cobalt oxide (NMC) are used as model systems. Various mixing methods, such as acoustic wave mixing, high-speed off-axis mixing, and thin film mixing, are compared. Their influence on ink viscosity and particle dispersion, coating thickness and microstructure uniformity, and electrolyte and electrode electrochemical properties will be discussed.

(Invited) Microwires Based on Carbon Nanotubes for Medicine and Biology

Flexible and biocompatible microwires are generally employed for biomedical implants in medicine, more specifically in neuroscience. These microwires used as electrodes need to be chemically inert and electrically conducting in order to record and stimulate the electrical activity of neurons in the nervous system. The electrodes available today are made of metals and silicon that lack the required flexibility resulting in a mechanical mismatch between soft tissues and rigid metals which induces faster biofouling and inconsistent performance for long-term implants. Biofouling triggered by inflammatory responses dramatically affects the performance of neural electrodes, resulting in decreased signal sensitivity and consistency over time. Thus, long-term clinical applications require electrically conducting flexible electrode materials with reduced dimensions and antibiofouling properties. These characteristics reduce the degree of inflammatory reactions and increase the lifetime of implanted neural electrodes. Carbon nanotubes (CNTs) are well known for their flexibility, electrical conductivity, and chemical inertness. This talk will report the fabrication of CNT fibers and subsequent coating using a biocompatible flexible polymer hydrogenated nitrile butadiene rubber (HNBR). Unlike the gold standard parylene-C coating that requires processing under vacuum, dissolved elastomer HNBR polymer can deposit uniform coating in solutions. Polymer dip-coating has been employed for uniform and continuous coating of meters-long CNT fibers of multiple diameters (26 to 66 mm) to evaluate the robustness of the approach. The polymer was able to provide uniform thickness and pinhole-free coating along the CNT fiber. Furthermore, the polymer has been shown to be biocompatible when tested with in vitro elusions and culturing neurons. The covalent functionalization of CNT microwire cross-section interfacing with the neurons using hydrophilic, anti-biofouling phosphorylcholine molecules displays reduced impedance and increased hydrophilicity. These CNT microwire assemblies are promising for the development of low-impedance neural electrodes with higher hydrophilicity and protein-fouling resistance to inhibit inflammatory responses.

Fabrication of organic thin films using slit nozzle with a wide viscosity spectrum

A slit nozzle with a broad viscosity spectrum is highly demanded for slit coating of various materials with different viscosities without a compromise on the film quality. To this end, we have fabricated a multi-cavity slit nozzle with the inlet and vent holes for each cavity. Compared with a slit nozzle with a high-volume single cavity, such a multi-cavity slit nozzle further reduces the dead volume and thus material waste. As a design parameter in computational fluid dynamics (CFD) simulations for the multi-cavity slit nozzles, we have calculated the coefficient of variation in the internal pressure (Pcv) of the cavity and investigated the correlation between the simulated Pcv value and the measured thickness uniformity of low-viscosity (tens of cPs) poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), medium-viscosity (5000 cPs) polydimethylsiloxane (PDMS), and high-viscosity (18,000 cPs) hard-PDMS films. It is addressed that the Pcv value that can ensure the thickness non-uniformity of less than 5 % is of the order of 1 %, and the internal pressure of the nozzle should not exceed a specific upper limit to protect a coating system against overload. Based on the design guideline provided, we have found that the upper limit of the viscosity spectrum of the triple-cavity slit nozzle with the 800-μm-thick shim is 79,000 cPs when the flow rate is 50 ml/min. Using the multi-cavity slit nozzle, we have fabricated a highly uniform PDMS film exhibiting the tensile strain as high as 180 %, which can be used as a substrate for stretchable displays. Furthermore, we have successfully fabricated flexible OLED stripes on the slit-coated conductive PEDOT:PSS stripes, showing the average luminance of 72.8 cd/m2 at 5 V and inter-stripe luminance non-uniformity as low as 8.2 %.

A Reflected-Light-Mode Multiwavelength Interferometer for Measurement of Step Height Standards.

The article is dedicated to measuring the thickness of step height standards using the author's version of the variable wavelength interferometer (VAWI) in the reflected-light mode, where the interference pattern is created by the combination of two Wollaston prisms. The element of novelty consists in replacing the traditional search for the coincidence of fringes in the object and background with a continuous measurement of their periods and phases relative to the zero-order fringe. The resulting system of sinusoids is then analyzed using two methods: the classical one and the second utilizing the criterion of uniform thickness. The theory is followed by simulation and experimental parts, providing insight to the metrological potential of the VAWI technology.

Van der Waals mid-wavelength infrared detector linear array for room temperature passive imaging.

Passive imaging for mid-wave infrared (MWIR) is resistant to atmospheric pollutants, guaranteeing image clarity and accuracy. Arrayed photodetectors can simultaneously perform radiation sensing to improve efficiency. Room temperature van der Waals (vdWs) photodetectors without lattice matching have evolved rapidly with optimized stacking methods, primarily for single-pixel devices. The urgent need to implement arrayed devices aligns with practical demands. Here, we present an 8 by 1 black phosphorus/molybdenum sulfide (BP/MoS2) vdWs photodetector linear array with a fill-factor of ~77%, fabricated using a temperature-assisted sloping transfer method. The flat interface and uniform thickness facilitate carrier transport and minimize pixel nonuniformities, showing an average peak detectivity (D*) of 2.34 × 109 cm·Hz1/2·W-1 in the mid-wave infrared region. Compared to a single pixel, push-broom scanning passive imaging is eight times more efficient and further enhanced through mean filtering and fast Fourier transform filtering for strip noise correction. Our study offers guidance on vdWs arrayed devices for engineering applications.

Mechanical performance analysis of functionally graded triply periodic minimal surfaces

To address the issue of a single gradient direction in the gradient design of triply periodic minimal surfaces, two functional gradient schemes, trapezoidal and W-shaped, were proposed based on the stress distribution range of the uniform thickness porous structure model using the primitive minimal surface porous structure. These structures were manufactured using a photosensitive resin through stereolithography additive manufacturing technology. Through finite element analysis and experimental validation, it was observed that as porosity decreases, the bending resistance of the uniform thickness model increases. The designed functional gradient porous structures were compared with the uniform thickness model. The results show that the designed gradient porous structure has a higher strength and bending stiffness than the uniform thickness porous structure. The proposed design can improve the bending performance of the porous structure. The W-shaped gradient porous structure with fine control of porosity variation range had better ability to improve structural bending performance than the trapezoidal gradient design.

Thickness uniformity, electrical properties, and stress of sputtered TiN thin films

Thickness uniformity, electrical properties, and stress of sputtered TiN thin films

Pan‐Antarctic Assessment of Ice Shelf Flexural Responses to Ocean Waves

AbstractUnderstanding the drivers of iceberg calving from Antarctic ice shelves is important for future sea level rise projections. Ocean waves promote calving by imposing stresses and strains on the shelves. Previous modeling studies of ice shelf responses to ocean waves have focused on highly idealized geometries with uniform ice thickness and a flat seabed. This study leverages on a recently developed mathematical model that incorporates spatially varying geometries, combined with measured ice shelf thickness and seabed profiles, to conduct a statistical assessment of how 15 Antarctic ice shelves respond to ocean waves over a broad range of relevant wave periods, from swell to infragravity waves to very long period waves. The results show the most extreme responses at a given wave period are generated by features in the ice shelves and/or seabed geometries, depending on the wave regime. Relationships are determined between the median ice shelf response and the median shelf front thickness or the median water cavity depth. The findings provide further evidence of the role of ocean waves in large‐scale calving events for certain ice shelves (particularly the Wilkins) and indicate a possible role of ocean waves in calving events for other shelves (Larsen C and Conger). Further, the relationships determined provide a method to assess the potential for increased calving as ice shelves evolve with climate change, and, hence, contribute to assessments of future sea level rise.

Stagnant rings and uniform film analysis of Phan-Thien Tanner fluid film flow on a vertically upward moving tube

Analyzing Phan-Thien Tanner fluid film behavior on a vertically upward moving tube can help predictive models in engineering, notably in coating and lubrication operations. This paper provides a theoretical analysis of the dynamics of stagnant rings and uniform Phan-Thien Tanner fluid film adhered to a vertically upward moving tube. Formulated ordinary differential equations are solved to get exact analytic expressions for velocity, flow rate, average velocity, shear stress components, and stagnant rings. Highly nonlinear algebraic equations are solved using Newton's method in MAPLE to find the linear and exponential Phan-Thien Tanner film thicknesses. The uniform film thickness widens with increasing constant tube velocity, while it decreases with increasing Deborah number, Stokes number, and elongation parameter. The analysis delineates that stagnant rings shrink around the tube as the Stokes number, Deborah number, and elongation parameter increase. The minimal Stokes condition for the existence of a realistic stagnant ring is also determined. It has been established that whenever the Stokes number is less than the minimal Stokes condition, stagnant rings do not form. A comparison between the exponential Phan-Thien Tanner, linear Phan-Thien Tanner, upper convected Maxwell, and Newtonian fluids is also provided for stagnant rings and fluid film thickness. Following the application of an efficient approximation on tube geometry, plate geometry is approximated, and the outcomes are consistent with existing literature. The results of this research are significant for a wide range of biofluid applications, including agrochemical uses, paint and surface coating flow behavior, thin films on the cornea and lungs, and chemical and nuclear reactor design.

Fracture resistance, marginal and internal adaptation of innovative 3D-printed graded structure crown using a 3D jet printing technology.

This in vitro study aimed to create a graded structured dental crown using 3D printing technology and investigate the fracture resistance and the adaptation of this new design. A dental crown with a uniform thickness of 1.5mm was designed, and the exported stereolithography file (STL) was used to manufacture 30 crowns in three groups (n = 10), solid (SC), bilayer (BL), and multilayer (ML) crowns using 3D jet printing technology. Marginal and internal gaps were measured using the silicone replica technique. Crowns were then luted to a resin die using a temporary luting agent and the fracture resistance was measured using a universal testing machine. One-way ANOVA and Tukey post hoc tests were used to compare the fracture resistance and the adaptation of crowns at a significance level of 0.05. Mean marginal and internal gap of the ML group were 80 and 82mm, respectively; which were significantly (p<0.05) smaller than BL (203 and 183mm) and SC (318 and 221mm) groups. The SC group showed the highest mean load at fracture (2330 N) which was significantly (p<0.05) higher than the BL (1716 N) and ML (1516 N) groups. 3D jet printing technology provides an opportunity to manufacture crowns in a graded structure with various mechanical properties. This study provided an example of graded structured crowns and presented their fracture resistance. SC group had the highest fracture resistance; however, ML had the best marginal and internal adaptation.