Complex 3D Structure Research Articles

Polarisation-independent ultrafast laser selective etching processing in fused silica.

In fused silica, ultrafast laser assisted etching enables high chemical etching rates (>300 μm h-1) by setting a light polarisation linear and perpendicular to the beam writing direction. However, for many non-planar surfaces and 3D structures, dynamic polarisation control is difficult or not yet possible to implement. In this contribution, we identify a laser inscription regime in which high etching rates are accomplished independently of the light polarisation. In this regime (<15 pulses per μm), we measure etching rates ∼300 μm h-1 (4 hours in NaOH) including femtosecond-pulse energies corresponding to type II modifications. Few pulse inscriptions show a low degree of anisotropy as compared to higher number of pulses, thus enabling the polarisation insensitivity whose mechanisms are discussed. To demonstrate the capabilities of the processing, we fabricate curved and square-wave microchannels together with a complex 3D geometrical structure (stellated octahedron) containing an inter-plane arrangement with challenging angles (45°), which are difficult to achieve even employing dynamic polarisation control.

Visualizing the Genome: Experimental Approaches for Live-Cell Chromatin Imaging

Over the years, our vision of the genome has changed from a linear molecule to that of a complex 3D structure that follows specific patterns and possesses a hierarchical organization. Currently, genomics is becoming "four-dimensional": our attention is increasingly focused on the study of chromatin dynamics over time, in the fourth dimension. Recent methods for visualizing the movements of chromatin loci in living cells by targeting fluorescent proteins can be divided into two groups. The first group requires the insertion of a special sequence into the locus of interest, to which proteins that recognize the sequence are recruited (e.g., FROS and ParB-INT methods). In the methods of the second approach, "programmed" proteins are targeted to the locus of interest (i.e., systems based on CRISPR/Cas, TALE, and zinc finger proteins). In the present review, we discuss these approaches, examine their strengths and weaknesses, and identify the key scientific problems that can be studied using these methods.

Fabrication of Complex Three-Dimensional Structures of Mica through Digital Light Processing-Based Additive Manufacturing

Mica is a group of clay minerals that are frequently used to fabricate electrical and thermal insulators and as adsorbents for the treatment of cationic pollutants. However, conventional subtractive manufacturing has the drawback of poor three-dimensional (3D) shape control, which limits its application. In this study, we propose digital light processing (DLP)-based additive manufacturing (AM) as one of the most effective ways to address this drawback. Two major challenges for the ceramic DLP process are the production of a homogeneous and stable slurry with the required rheological properties and the maintenance of printing precision. The mica green body was fabricated using a 53 vol.% solid loading slurry through DLP, which exhibited good dimensional resolution under an exposure energy dose of 10 mJ/cm2. The precise, complex 3D structure was maintained without any defects after debinding and sintering at 1000 °C. The use of ceramic AM to overcome the shape-control limitations of mica demonstrated in this study offers great potential for expanding the applications of mica.

A constitutive model and its numerical implementation for reversible behavior of shape memory hydrogels

Shape memory hydrogels (SMHs) are kinds of smart materials with great importance in many fields, such as drug release and soft robotics. In order to design the structures base on SMHs, it is necessary to reveal the mechanism of the shape memory effect and establish the constitutive model of SMHs. However, the existing constitutive models can not describe some of important mechanical behavior of SMHs, such as reversible shape memory effects. In this paper, a three-dimensional finite deformation constitutive model is developed for SMHs with reversible shape memory effects caused by the conformation transition of N-isopropylacrylamide (PNIPAM). In order to well capture its reversible shape memory effect, the polymer network for PNIPAM is decomposed into two parts, coil PNIPAM and globule PNIPAM, with different reference configurations. Then this model is implemented into a user material subroutine (UMAT) and is used for simulating the equilibrium swelling, isothermal uniaxial tension, reversible shape memory behavior and multiple shape memory cycles of SMHs. Our model is validated by comparing the simulation results with experiments. The deformation of a more complex 3D structure and a bilayer structure containing SMHs are also numerically studied which demonstrates great potential of our model in exploring the application of SMHs.

Quantitative characterization of 3D structure of vellus hair arrector pili muscles by micro CT.

Vellus hair is the fine, wispy hair found over most of the body surface, and the arrector pili muscles (hair muscle) serve to raise these hairs. Hair muscles are also critical for skin regeneration, contributing to the maintenance of stem cells in epidermis and hair follicles. However, little is known about their fundamental properties, especially their structure, because of the limitations of conventional two-dimensional histological analysis. We aimed to quantitatively characterize the structure of vellus hair muscles by establishing a method to visualize the 3D structure of hair muscle. We observed young female abdominal skin specimens by means of X-ray micro CT and identified hair muscles in each cross-sectional CT image. We then digitally reconstructed the 3D structure of the hair muscles on computer (digital-3D skin), and numerically evaluated their structural parameters. Vellus hair muscles were clearly distinguished from the surrounding dermal layer in X-ray micro CT images and were digitally reconstructed in 3D from those images for quantification of the structural parameters. The mean value of number of divisions of vellus hair muscles was 1.6, mean depth was 943.6 μm from the skin surface, mean angle to the skin surface was 28.8 degrees, and mean length was 1657.9μm. These values showed relatively little variation among subjects. The mean muscle volume was approximately 20 million μm3 but showed greater variability than the other parameters. Digital-3D skin technology is a powerful approach to understand the tiny but complex 3D structure of vellus hair muscles. The fundamental nature of vellus hair muscles was characterized in terms of their 3D structural parameters, including number of divisions, angle to the skin surface, depth, and volume.

Abstract 74: Single-cell 3D spatial omics for tumor hypoxia

Abstract Tumor hypoxia arises from the abnormal vasculature in tumors which limit the oxygen supply to the rapidly growing cancer cells. To acclimate to this deprived microenvironment, cancer cells upregulate hypoxia-inducible factor 1-alpha (HIF-1) signaling pathway priming themselves towards more aggressive and heterogeneous phenotypes. Hence, tumor hypoxia becomes a major obstacle for effective cancer treatment. Deciphering hypoxia-driven tumor heterogeneity within the tumors is essential to understanding cancer biology and developing novel therapeutic strategies. A stronger focus should be directed towards the effect of hypoxia types and levels rather than just the absence or presence of hypoxia since hypoxia is heterogeneous in the three-dimensional (3D) tumor microenvironment (TME). There are acute and chronic types of tumor hypoxia, and the hypoxia levels are also variable, forming unpredictable and irregular 3D hypoxic areas. Although traditional techniques (i.e., single-cell RNA sequencing (scRNA-seq), immunohistochemistry (IHC), and immunofluorescence (IF)) and innovative spatial transcriptomics have been developed and applied for investigating tumor cell heterogeneity. Underlying issue of missing spatial information, limited numbers of the biomarker detection, underrepresentation of 3D tumor structure, or limited analyzed area onto the array chip size exist respectively in these methods. The objective of this project is to develop a 3D spatial genomics approach with single-cell resolution, named sc3DSG, as an advanced spatial transcriptomic method to study hypoxia-driven cancer cell heterogeneity in 3D. Given that, I developed a 3D cellular fluorescence barcoding method by microscopic photobleaching in tumor macro-sections. The barcodes would maintain a fluorescent footprint of cells in different hypoxic areas upon tissue dissociation. Cells encoded with varied barcodes could be differentiated on flow cytometry and further sorted into separate groups for scRNA-seq. With the optimization with RNA preservation reagent in the workflow, sc3DSG achieves high-quality and high-yield RNA transcript for unbiased transcriptomic analysis. In summary, sc3DSG is an advanced spatial transcriptomic method including a sequential workflow of photobleaching barcoding, tissue dissociation, fluorescence-activated cell sorting (FACS), and scRNA-seq. Sc3DSG enables the study of tissue molecular features without losing spatial information and is a better fit for the study of complex 3D structure like vessels or tumor hypoxia. This approach will unravel hypoxia-driven bimolecular and cellular features by considering the degrees and types of tumor hypoxia. Citation Format: Yi-Chien Wu, Steve Seung-Young Lee. Single-cell 3D spatial omics for tumor hypoxia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 74.

A new metaheuristic optimization based on K-means clustering algorithm and its application to structural damage identification

This paper develops a new metaheuristic optimization algorithm named K-means Optimizer (KO) to solve a wide range of optimization problems from numerical functions to real-design challenges. First, the centroid vectors of clustering regions are established at each iteration using K-means algorithm, then KO proposes two movement strategies to create a balance between the ability of exploitation and exploration. The decision on the movement strategy for exploration or exploitation at each iteration depends on a parameter that will be designed to recognize if each search agent is too long in the region visited with no self-improvement. To demonstrate the effectiveness and reliability of KO, twenty-three classical benchmark functions, CEC2005 and CEC2014 benchmark functions, are employed as a first example and compared with other algorithms. Then, three well-known engineering problems are also considered and their results are compared to the results obtained by the other algorithms. Finally, KO is applied to structural damage identification (SDI) problem of a complex 3D concrete structure including seven stories building having a 25.2 m total height. For this purpose, SAP2000 is used to solve the finite element (FE) model of this structure. Then, for the first time, we successfully developed a sub-program that allows two-way data exchange between SAP2000 and MATLAB through the Open Application Programming Interface (OAPI) library to update the FE model. From the results, we found that KO has the best performance for the considered benchmark functions based on the Wilcoxon rank-sum test and Friedman ranking test. The results obtained in this work have proved the effectiveness and reliability of KO in solving optimization problems, especially for SDI. Source codes of KO is publicly available at http://goldensolutionrs.com/codes.html.

Laminar forced convection heat transfer around wavy elliptic cylinders with different aspect ratios

The present study investigates the forced convection heat transfer around the wavy elliptic cylinders by considering wide range of wavelength (λ) for different aspect ratios (AR). The wake thermal structures were classified into four modes of the quasi-2D unsteady, quasi-2D steady, complex 3D unsteady and 3D steady structures, which is mapped in AR-λ plane. The short wavelengths formed the quasi-2D thermal structure for both steady and unsteady forced convections. The quasi-2D unsteady structure is characterized by the spanwise nearly invariant isothermal structures and the periodical time evolution of the Nusselt number. The long wavelengths formed the 3D thermal structure in the present range of AR. The complex 3D unsteady thermal structure is featured by the hole and spanwise separated formation of the temperature iso-surface owing to the vortex dislocation and hairpin vortex formation. The 3D steady thermal structure also appeared in the steady regime and the spanwise dependence of the thermal structure became considerable with decreasing AR. The surface distribution of the mean Nusselt number depended on the regime of the thermal structures. In the long wavelength region, the additional appearance of two types of the streamwise vorticities locally attenuated the heat transfer by weakening the reverse flow in the near wake. As the cylinder becomes more elliptic, the two types of the streamwise vorticities becomes weak and finally disappears, resulting in weakening the effect of the local attenuation of the heat transfer. Therefore, it can be concluded that the streamlined shape is predominant to the stabilization of the forced convection with decreasing AR, regardless of the wavelength .

3D porosity structure of the earliest solar system material

Carbonaceous chondrites (CCs) contain the earliest preserved Solar System material, and objects containing this material are targets of numerous sample return missions. Both laboratory and remote sensing data have shown that this material can be highly porous, but the origin and nature of this porosity is currently not well understood. Because the majority of porosity within CCs is submicron to micron in size, previous lab efforts have been restricted by the limited observational scale required to examine this porosity with currently available techniques. Here we present results from a newly developed technique that allows submicron porosity to be examined in 3D within a 12 mm3 volume of CM Murchison. We use X-ray computed tomography combined with the highly attenuating noble gas xenon to characterize porosity well below the spatial resolution of the data (3.01 µm/voxel). This method not only allows examination of submicron porosity within a significantly larger volume than previously possible but also reveals the full three-dimensional porosity structure and pore connectivity. Our data reveal that some fine-grained rims (FGRs) surrounding chondrules have a complex 3D porosity structure, suggesting formation of the FGRs via dust aggregates or variable secondary processing around the rim after accretion.

An Optimized Method to Decellularize Human Trabecular Meshwork.

Glaucoma is linked to raised intraocular pressure (IOP). The trabecular meshwork (TM) plays a major role in regulating IOP by enabling outflow of aqueous humor from the eye through its complex 3D structure. A lack of therapies targeting the dysfunctional TM highlights the need to develop biomimetic scaffolds that provide 3D in vitro models for glaucoma research or as implantable devices to regenerate TM tissue. To artificially mimic the TM’s structure, we assessed methods for its decellularization and outline an optimized protocol for cell removal and structural retention. Using bovine TM, we trialed 2 lysing agents—Trypsin (0.05% v/v) and Ammonium Hydroxide (NH4OH; 2% v/v). Twenty-four hours in Trypsin caused significant structural changes. Shorter exposure (2 h) reduced this disruption whilst decellularizing the tissue (dsDNA 26 ± 14 ng/mL (control 1970 ± 146 ng/mL)). In contrast, NH4OH lysed all cells (dsDNA 25 ± 21 ng/mL), and the TM structure remained intact. For human TM, 2% v/v NH4OH similarly removed cells (dsDNA 52 ± 4 ng/mL (control 1965 ± 233 ng/mL)), and light microscopy and SEM presented no structural damage. X-ray computed tomography enabled a novel 3D reconstruction of decellularized human TM and observation of the tissue’s intricate architecture. This study provides a new, validated method using NH4OH to decellularize delicate human TM without compromising tissue structure.

Variational Level Set Method for Topology Optimization of Origami Fold Patterns

AbstractWith specific fold patterns, a 2D flat origami can be converted into a complex 3D structure under an external driving force. Origami inspires the engineering design of many self-assembled and re-configurable devices. This work aims to apply the level set-based topology optimization to the generative design of origami structures. The origami mechanism is simulated using thin shell models where the deformation on the surface and the deformation in the normal direction can be simplified and well captured. Moreover, the fold pattern is implicitly represented by the boundaries of the level set function. The folding topology is optimized by minimizing a new multiobjective function that balances kinematic performance with structural stiffness and geometric requirements. Besides regular straight folds, our proposed model can mimic crease patterns with curved folds. With the folding curves implicitly represented, the curvature flow is utilized to control the complexity of the folds generated. The performance of the proposed method is demonstrated by the computer generation and physical validation of two thin shell origami designs.

Investigating the Fibrillar Ultrastructure and Mechanics in Keloid Scars Using In Situ Synchrotron X-ray Nanomechanical Imaging

Fibrotic scarring is prevalent in a range of collagenous tissue disorders. Understanding the role of matrix biophysics in contributing to fibrotic progression is important to develop therapies, as well as to elucidate biological mechanisms. Here, we demonstrate how microfocus small-angle X-ray scattering (SAXS), with in situ mechanics and correlative imaging, can provide quantitative and position-resolved information on the fibrotic matrix nanostructure and its mechanical properties. We use as an example the case of keloid scarring in skin. SAXS mapping reveals heterogeneous gradients in collagen fibrillar concentration, fibril pre-strain (variations in D-period) and a new interfibrillar component likely linked to proteoglycans, indicating evidence of a complex 3D structure at the nanoscale. Furthermore, we demonstrate a proof-of-principle for a diffraction-contrast correlative imaging technique, incorporating, for the first time, DIC and SAXS, and providing an initial estimate for measuring spatially resolved fibrillar-level strain and reorientation in such heterogeneous tissues. By application of the method, we quantify (at the microscale) fibrillar reorientations, increases in fibrillar D-period variance, and increases in mean D-period under macroscopic tissue strains of ~20%. Our results open the opportunity of using synchrotron X-ray nanomechanical imaging as a quantitative tool to probe structure–function relations in keloid and other fibrotic disorders in situ.

3D and 4D Printing of Complex Structures of FeMnSi‐Based Shape Memory Alloy Using Laser Powder Bed Fusion

AbstractThe additive manufacturing of shape memory materials, commonly known as 4D printing, facilitates the achievement of a complex 3D structure that possesses a temperature‐dependent shape change functionality. Herein, it is demonstrated that complex 3D structures of Fe‐based shape memory alloys (Fe‐SMAs) can be produced through a 3D printing process of laser powder bed fusion (L‐PBF). The 3D printed Fe‐SMA shows good mechanical properties with much higher strength and stiffness than those in shape memory polymers. The printed Fe‐SMAs manifest shape recovery behavior, demonstrating that material‐inherent functional behaviors can be combined with the functionalities of the complex 3D structures to facilitate shape morphing, self‐healing, and auxetic behavior and to achieve a lattice structure with extraordinary specific strength.

Mitigation of transient ground potential rise in gas insulated substations during very fast transient overvoltage

• The paper proposes PEEC based a simulation technique the allow to take into account the complex 3D structure and the various electromagnetic coupling phenomena that take place between the metallic structure of a complex GIS and the associated earthing system during VFTO events. • The proposed GIS modeling and simulation technique is applied in case of 110 kV GIS in order to identify the grounding grid area that mostly effect the clearance of VFTO fault. • A mitigation procedure is show cased for the identified grounding grid area in order to accelerate the clearance of VFTO faults. This paper is focused on the assessment and mitigation of the transient response of a Gas Insulated Substation's (GIS) grounding grid to the fault due to voltage breakdown using the Partial Element Equivalent Circuit (PEEC) numerical approach. The adopted analysis methodology considers the magnetic induction by quantifying the electromagnetic couplings generated within the metallic components contained by the GIS configuration. The Transient Ground Potential Rise (TGPR) and transient current are computed and analyzed at several locations inside of GIS housing. With the aid of 3D graphical representation, the maximum amplitudes of the TGPR across the substation are illustrated. The mitigation efforts are considerably optimized by assuming the grounding grid sub-system is responsible for high frequency fault energy clearance based on identification method. By adopting several simplifications of the earthing system during the computational process, from a step-by-step analysis, it has been discovered that the grid located beneath the GIS enclosure will mostly attenuate the TGPR across the GIS building. Based on the aforementioned findings a successful mitigation technique is implemented.

Chiral columns forming a lattice with a giant unit cell.

Mesogenic materials, quinoxaline derivatives with semi-flexible cores, are reported to form a new type of 3D columnar phase with a large crystallographic unit cell and Fddd lattice below the columnar hexagonal phase. The 3D columnar structure is a result of frustration imposed by the arrangement of helical columns of opposite chiralities into a triangular lattice. The studied materials exhibit fluorescence properties that could be easily tuned by modification of the molecular structure; for compounds with the extended π electron conjugated systems the fluorescence is quenched. For molecules with a flexible structure the fluorescence quantum yield reaches 25%. On the other hand, compounds with a more rigid mesogenic core, for which the fluorescence is suppressed, show effective photogeneration of charge carriers. For some materials bi-polar hole and electron transport was observed.

Gate-oxide-short defect analysis and fault modeling in FinFETs

FinFET has caused new challenges in reliable device testing due to its three-dimensional structure and reduced critical dimensions. Accurate defect modeling and generation of reliable fault models are essential to create realistic set of test patterns to detect defects. Cell-Aware Test (CAT) has significantly improved the detection of cell-internal defects in MOSFET-based circuits. However, the defect models utilized are obtained based on the defects injected at the layout level and represented by fixed lumped passive components that cannot reflect the true defect nature in the complex 3D structure of FinFET. Gate-oxide-short (GOS) is one of the defects that has significant impact on circuit reliability. This paper focuses on the 3D physical device structure, rather than the layout. The analysis is based on the 3D bulk FinFET template provided by Synopsys. We have performed DC and transient simulations on defective FinFETs with various defect locations and sizes in the Sentaurus TCAD environment. The comprehensive investigation of the GOS defect has led to the development of accurate defect models. These models are applied as Verilog-A modules in circuit-level simulation of complex logic gates such as And-Or-Invert (AOI) and 3:1 Multiplexer (MUX). We have also extracted the HSPICE model parameters for the FinFET template based on the BSIM-CMG local extraction procedure. The proposed fault modeling methodology is compared to the existing CAT-based approach and demonstrated its superiority. Our methodology is not limited to standard library cells, as the defect models are developed at the device 3D structure instead of the layout.

3D Visualization of Bamboo Node’s Vascular Bundle

The vascular bundle is an important structural unit that determines the growth and properties of bamboo. A high-resolution X-ray microtomography (μCT) was used to observe and reconstruct a three-dimensional (3D) morphometry model of the vascular bundle of the Qiongzhuea tumidinoda node due to its advantages of quick, nondestructive, and accurate testing of plant internal structure. The results showed that the morphology of vascular bundles varied significantly in the axial direction. In the cross-section, the number of axial vascular bundles reached a maximum at the lower end of the sheath scar, and the minimum of it was at the middle of the diaphragm. The frequency of axial vascular bundles decreased from the lower end of the node to the nodal ridge, and subsequently increased until the upper end of the bamboo node. The proportion of parenchyma, fibers, and conducting tissue was 65.7%, 30.5%, and 3.8%, respectively. The conducting tissues were intertwined to form a complex 3D network structure, with a connectivity of 94.77%. The conducting tissue with the largest volume accounted for 60.26% of the total volume of the conducting tissue. The 3D-distribution pattern of the conducting tissue of the node and that of the fibers were similar, but their thickness changed in the opposite pattern. This study revealed the 3D morphometry of the conducting tissue and fibers of the bamboo node, the reconstruction of the skeleton made the morphology more intuitive. Quantitative indicators such as the 3D volume, proportion, and connectivity of each type of tissue was obtained, the bamboo node was enlarged mainly caused by the particularly developed fibers. This work laid the foundation for a better understanding of the mechanical properties and water transportation of bamboo and revealed the mystery of bamboo node shedding of Q. tumidinoda.

Engineering of Extracellular Matrix‐Like Biomaterials at Nano‐ and Macroscale toward Fabrication of Hierarchical Scaffolds for Bone Tissue Engineering

The increasing rate of musculoskeletal pathologies has compelled the development of improved and novel treatment strategies in order to address unmet clinical needs. Tissue engineering approaches comprising the use of scaffolds for bone regeneration have been showing to be a promising alternative to conventional bone repair/substitution approaches. In particular, hierarchical scaffolds as methods of structural support and osteogenic differentiation promoters are among the most used tools in bone tissue engineering (BTE). In this reasoning, hierarchical scaffolds have sparked the field, striving toward mimicking the natural bone tissue in both, its complex 3D structure and composition. A recent and promising trend has been the merging of nanotechnology and tissue engineering concepts. As such the incorporation of nanoparticles and nanocomposites into micro‐ or macroscaffold systems can result in an improvement of scaffolds’ biofunctionality at different levels. These tools are versatile in nature and can be used for multiple purposes such as drug delivery, thermal conductors, and mechanical reinforcement. Taking into consideration multidisciplinary approaches, several strategies have been pursued. The recent reports dealing with the approaches pursued in the hierarchical scaffolds production and enhancement, ranging from the nanoscale to the macroscale, are overviewed herein.

Detecting High-Rise Buildings from Sentinel-2 Data Based on Deep Learning Method

High-rise buildings (HRBs) as a modern and visually distinctive land use play an important role in urbanization. Large-scale monitoring of HRBs is valuable in urban planning and environmental protection and so on. Due to the complex 3D structure and seasonal dynamic image features of HRBs, it is still challenging to monitor large-scale HRBs in a routine way. This paper extends our previous work on the use of the Fully Convolutional Networks (FCN) model to extract HRBs from Sentinel-2 data by studying the influence of seasonal and spatial factors on the performance of the FCN model. 16 Sentinel-2 subset images covering four diverse regions in four seasons were selected for training and validation. Our results indicate the performance of the FCN-based method at the extraction of HRBs from Sentinel-2 data fluctuates among seasons and regions. The seasonal change of accuracy is larger than that of the regional change. If an optimal season can be chosen to get a yearly best result, F1 score of detected HRBs can reach above 0.75 for all regions with most errors located on the boundary of HRBs. FCN model can be trained on seasonally and regionally combined samples to achieve similar or even better overall accuracy than that of the model trained on an optimal combination of season and region. Uncertainties exist on the boundary of detected results and may be relieved by revising the definition of HRBs in a more rigorous way. On the whole, the FCN based method can be largely effective at the extraction of HRBs from Sentinel-2 data in regions with a large diversity in culture, latitude, and landscape. Our results support the possibility to build a powerful FCN model on a larger size of training samples for operational monitoring HRBs at the regional level or even on a country scale.

A novel flow-based geometrical upscaling method for representing fault zones with two-phase fault rock properties into a dynamic reservoir model

Faults are generally represented in conventional upscaled models as 2D planar surfaces with transmissibility multipliers used to represent single-phase fault properties. However, faults are structurally complex 3D zones in which both single-phase and two-phase fault rock properties can be significant. Ignoring this structural and petrophysical complexity within faults may impart considerable inaccuracy on the predictive performance of upscaled models. This study has developed a two-phase flow-based geometrical upscaling method capable of representing simultaneously the complex geometry and saturation-dependent two-phase flow properties of realistic fault zones. In this approach, high-resolution sector models are built of small portions of the fault zones and assigned appropriate single-phase and two-phase fault rock properties. Steady state two-phase flow simulations at different fractional flows of oil and water are used to determine the saturation dependent upscaled pseudo relative permeability functions which are incorporated into upscaled models. The method is applied to an example model containing two 3D fault zone components and tested by comparing the flow results of upscaled model with those of a high-resolution truth model. Results show that two-phase flow-based geometrical upscaling is a promising method for representing the effects of two-phase fault rock properties and complex 3D fault zone structure simultaneously.