3D Form Research Articles

3D knit pneumatic actuators for wearable haptic displays

Weft knit textiles are growing in popularity as materials for soft robotic applications due to their scalability and near infinite mechanical tunability. We leverage the benefits of 3D weft knitting to develop a novel method of manufacturing small scale (5-8 mm) pneumatic actuators that can be embedded across a distributed textile surface. Weft knitting (i.e., intarsia) enables seamless transitions between contrasting yarns and textile structures, which increases manufacturing resolution for small-scale actuators. Additionally, weft knitting enables mechanical property tunability beyond what is available off the shelf, enabling customizable actuation behavior. We demonstrate that 3D knit textile actuation properties, such as blocking force, free displacement, and bending stiffness, can be tuned by manipulating actuator design parameters, including (1) yarn tensile stiffness, (2) textile structural strain, (3) local textile geometry, and (4) input pressure. To demonstrate the manufacturability and scalability within a 3D wearable form factor, we build a haptic glove prototype with surface embedded actuation to mimic the sensation of touching and grasping virtual objects.

Emotion recognition from EEG signal enhancing feature map using partial mutual information

The brain signal is the most potent information source to recognize emotion, a fundamental trait of human beings, for providing various emerging personalized courtesies or services instantly to individuals. For emotion recognition (ER), Electroencephalography (EEG) is a preferred brain signal, where the crucial and challenging task is accurately extracting features from complex EEG signals using appropriate computational intelligence or machine learning techniques. Recent ER methods mostly use EEG channel connectivity features to identify the emotion. Specifically, to construct a connectivity feature map (CFM), Pearson correlation coefficient (PCC), mutual information (MI), normalized MI (NMI), and a few other techniques are used. Notably, in the existing ER methods, CFMs are predominantly in the two-dimensional (2D) form, i.e., using the signals from two EEG channels. This study proposes an enhanced CFM that uses partial MI (PMI) by introducing an extra third channel to expose more information and strengthen the feature extraction ability of ER. The proposed technique calculates the PMI-based connectivity features for each pair of EEG channels and presents CFM in 2D and 3D forms. Convolutional Neural Network (CNN) is used to classify emotion using 2D and 3D CFMs. In creating CFMs from EEG signals, rigorous tests have been performed on the DEAP benchmark EEG dataset. As PMI exposed additional information, the enhanced CFM has been found to deliver better ER performances than the one that uses typical MI or NMI, revealing the proposed one outperforming the existing related contemporary methods.

DFT studies on structural stability, vibrational and linear and nonlinear optical properties of low-dimensional zinc sulfide: from the 3D bulk to the 2D monolayer and the 1D zigzag single-walled nanotubes

Through first-principles calculations, we investigate structural stability, vibrational and linear and nonlinear optical properties of the zinc sulfide (ZnS) in different periodic forms ranging from the 3D bulk to the 2D hexagonal monolayer and their corresponding 1D zigzag single-walled nanotubes. To first order, the electronic wave function on the ground state was constructed using linear combinations of Gaussian-type functions at the DFT/B3LYP level. Then, the Raman and IR spectrum is computed by adopting a Coupled-Perturbed-Hartree–Fock/Kohn–Sham (CPHF/KS) approach. Cohesive, relaxation, and rolling energies, elastic and piezoelectric constants, electronic and nuclear contributions to the polarizability tensor, and nonlinear first and second-order hyperpolarizability tensor components are reported. Our study shows that 3D and 2D forms are stable and show semiconducting behavior, good piezoelectric responses, and fascinating linear and nonlinear optical properties. For 1D single-walled nanotubes, dynamic stability is observed only for the smallest (6,0) nanotubes. For n > 6, imaginary mode frequencies in the simulated IR and Raman spectra indicate dynamic instability. A scanning mode procedure along the largest imaginary vibrational mode is applied in order to determine the stable structures of the largest (14,0), (18,0) and (22,0) ZnS nanotubes. After that, no more imaginary phonon frequencies are detected in their vibrational spectra. Their potential energy surface contains two minima between a saddle point corresponding to a slightly distorted nanotube structure. Our study proves that the zinc sulfide nanostructures possess diverse physical properties so useful for potential applications in nanoelectronics and for nanodevices.

Paul Ricoeur's Hermeneutic Analysis on User Interface Design for Augmented Reality Baleganjur Applications

Augmented reality technology or more popularly known as AR is a technology that implements interactive multimedia concepts. Augmented reality technology is a technology that combines the virtual world with the real world in real-time, through electronic devices such as cameras, sensors and software, augmented reality is able to display virtual objects in both 2D and 3D form in the real world. In this study, it focuses on analyzing the appearance of the interface design or the main menu application user interface by implementing augmented reality technology, with the name of the application, Augmented Reality Baleganjur. The user interface display on the main menu of the Baleganjur Augmented Reality application has design elements that can be translated with different meanings and understandings, depending on the user's point of view. This is the basis of this research, where the appearance of the user interface design on the main menu of the Baleganjur Augmented Reality application has design elements that can lead to different interpretations of meaning and understanding. The purpose of this study is of course to reveal the meaning and understanding of the design elements in the user interface design display of the Baleganjur Augmented Reality application, by conducting an in-depth analysis using Paul Ricoeur's Hermeneutics. As for the results of this study, it can be concluded that researchers as hermeneutics have an important role in interpreting and offering solutions, which can later be used as a reference for repairing or perfecting design elements in the application user interface, so that these design elements can convey meaning and understanding in a comprehensive and detailed manner to users.

Thermoformability study of wood flour–HDPE composites with variations in wood content under vacuum forming

Wood–plastic composites (WPCs) have emerged as sought-after substitutes for plastic. However, their use is restricted primarily to linear profiles owing to the lack of techniques for their three-dimensional (3D) forming. Thermoforming is a potential method for the 3D formation of WPCs. Accordingly, the aim of this study was to evaluate the thermoforming behaviour of extruded wood flour–high-density polyethylene composites with two different wood flour compositions (34 % and 54 %) under vacuum forming. This study examined the thermal behaviour of each structure during the forming process and the shape conformability, shape consistency, and surface quality of the formed samples. The findings suggest that increasing the quantity of plastic in composites can improve the obtained shape dimensions. Nevertheless, this improvement is accompanied by an increased level of inconsistency in the acquired profiles due to the distinct stretching rates of plastic and wood. Furthermore, the results reinforced the reliability of thermal analysis as a credible means of evaluating quality.

A Study of 3D model voxelization method for artificial intelligence learning

<p class="abstract">The 3D reconstruction technology which is one of various restoration technologies, implements and shapes 2D pixels of an object that actually exists in a 3D form. As an accurate 3D model for artificial intelligence learning information pre-processing is required. The pre-processing needs to accurately size information and coordinate information of a 3D object for artificial intelligence learning. Also, the 3D model data generated during the preprocessing can be represented as a point cloud, which is point-based coordinate data. In this study, the pixel data was analyzed by voxelizing the 3D model for artificial intelligence learning, and the 3D model data was digitized to form a mesh file. In this study, 3D modeling was done with a 3D modeling tool and the object was exported to STL. In addition, it was converted into mesh file data including 3D coordinate data in Python language on Google’s colab platform. The mesh data created in this way is used in DataSet for artificial intelligence learning (CNN, RNN, GAN). Currently, there are many datasets for 2D artificial intelligence learning, but this study provided an opportunity to collect 3D artificial intelligence learning datasets. The research results can be used in the fields of robots, autonomous driving, games, and product design.</p>

Anomalous tensile strength and thermal expansion, and low thermal conductivity in wide band gap boron monoxide monolayer

Most recently the formation of boron monoxide (BO) in the two-dimensional (2D) form has been confirmed experimentally (J. Am. Chem. Soc. 2023, 145, 14660). Motivated by the aforementioned finding, herein we theoretically explore the key physical properties of the single-layer and suspended BO. Density functional theory (DFT) results reveal that BO monolayer yields a large indirect band gap of 3.78 (2.18) eV on the basis of HSE06(PBE) functional. Ab-initio molecular dynamics results reveal the remarkable thermal stability of the BO monolayer at 1000 K. The thermal and mechanical properties at room temperature are furthermore investigated using a machine learning interatomic potential (MLIP). The developed MLIP-based model close to the ground state could very precisely reproduce the DFT predictions for the mechanical properties of the BO monolayer. The elastic modulus, tensile strength and lattice thermal conductivity of the BO monolayer at room temperature are predicted to be 107 GPa, 25 GPa and 5.6 ± 0.5 W/mK, respectively. At the room temperature the BO monolayer is noticeably predicted to yield an ultrahigh negative thermal expansion coefficient, by almost 17 folds larger than that of the single-layer graphene. The presented results reveal the large indirect electronic band gap, decent thermal and dynamical stability, anomalously low elastic modulus to tensile strength ratio, ultrahigh negative thermal expansion coefficients and low lattice thermal conductivity of the BO monolayer.

Anchored Cell Sheet Engineering: A Novel Scaffold‐Free Platform for in vitro Modeling

AbstractBiofabricated in vitro models hold unrealized potential in accelerating drug discovery and reducing new drug costs, but current models are overly simplified and lack physiological relevance. Certain platforms capable of mimicking in vivo conditions face hurdles such as complexity, high costs, and non‐standardized applications. Existing cell sheet engineering methodologies, despite being physiologically relevant, have technical limitations like creating suitable 3D forms with proper anchorage. An innovative platform is introduced here, designed for in vitro modeling, which capitalizes on 2D culture systems and scaffold‐free cell sheets to create self‐assembling 3D tissue constructs. It provides precise control over cellular behavior, especially ECM production and remodeling. Scaffold‐free muscle fibers and lung epithelial cell cultures served as examples. This platform can fuse various scaffold‐free models to construct assembloids mimicking organ structures and functions. Different tissues can be linked via a fluidic system for body‐level simulations. Moreover, ECM‐rich constructs from cell sheets can create organ‐level ECM scaffolds, and the resulting cell sheet‐derived ECM (CSdECM) can be solubilized to facilitate 2D cellular behavior. This versatile platform, compatible with other cell sheet engineering techniques, is set to revolutionize in vitro modeling.

Improvement on the wire EDM characteristics of zirconia filled Al7050 (Al-Zn-Cu-Mg) alloy composite using Taguchi coupled TOPSIS method

Wire electrical discharge machining (WEDM) is an cutting edge non-traditional techniques for producing complicated 3D forms in rigid materials with greater dimensional accuracy. The aim of the investigation was, to predict the WEDM characteristics of ZrO2 ceramic addition of Al7050 alloy composite by employing Taguchi coupled Technique for order preference by similarity to ideal solution (TOPSIS) approach. The work material was manufactured by stir casting process utilizing 12 wt.% of ZrO2 particulates in Al7050 alloy matrix. The experimental work was carried out as per the L9 (33) orthogonal array design by taking input parameters like pulse current ( Ip), pulse on-time ( Ton) and pulse off-time ( Toff), respectively. The impact of the WEDM parameters on the material removal rate (MRR) and surface roughness (SR) were determined by analysis of variance (ANOVA). Based on the TOPSIS approach, the higher MRR (0.32251 g/min) with lesser SR (3.982 µm) were achieved at the ‘ Ip’ of 25 amps, ‘ Ton’ of 115 µs and ‘ Toff’ of 60 µs. ANOVA results explored that the ‘ Ton’ was identified as the primary impact factor on MRR and SR, subsequently by ‘ Ip’ and ‘ Toff’ with contribution of 44.23%, 36.53%, and 12.16%, respectively. Moreover, the surface topography of the machined composite surface was analyzed through scanning electron microscopy (SEM). It was clearly revealed the formation of surface defects such as craters, micropores, cracks and also the appearance of a recast layer on the machined surface.

Symmetry and complexity: A Lie symmetry approach to bifurcation, chaos, stability and travelling wave solutions of the (3+1)-dimensional Kadomtsev-Petviashvili equation

This work delves into the investigation of the nonlinear dynamics pertaining to the (3+1)-dimensional Kadomtsev-Petviashvili equation, which describes the propagation of long-wave with dissipation and dispersion in nonlinear media. The research entails an exploration of symmetry reductions using Lie group analysis, an analysis of the dynamical system’s characteristics through bifurcation phase portraits, and a study of the perturbed dynamical system’s dynamic behavior through chaos theory. Chaotic behavior is identified using various tools for detecting chaos, including the Lyapunov exponent, 3D phase portrait, Poincare map, time series analysis, and an exploration of the presence of multistability in the autonomous system under different initial conditions. Additionally, the research applies the unified Riccati equation expansion method to solve the considered equation analytically and constructs the general solutions of solitary wave solutions such as trigonometric function solutions, periodic and singular soliton solutions. These solutions come with their associated constraint conditions and are demonstrated through visual representations in the form of 2D, 3D, and density plots with carefully selected parameters. Furthermore, the stability analysis of the considered equation is also discussed and shown graphically. The results of this work are relevant and have applications in describing the propagation of long-wave with dissipation and dispersion in nonlinear media.

On a 3D material modelling of smart nanocomposite structures

Smart composites (SCs) are utilized in electro-mechanical systems such as actuators and energy harvesters. Typically, thin-walled components such as beams, plates, and shells are employed as structural elements to achieve the mechanical behavior desired in these composites. SCs exhibit various advanced properties, ranging from lower order phenomena like piezoelectricity and piezomagneticity, to higher order effects including flexoelectricity and flexomagneticity. The recently discovered flexomagneticity in smart composites has been investigated under limited conditions. A review of the existing literature indicates a lack of evaluation in three-dimensional (3D) elasticity analysis of SCs when the flexomagnetic effect (FM) exists. To address this issue, the governing equations will incorporate the term ∂/∂z, where z represents the thickness coordinate. The variational technique will guide us in further developing these governing equations. By using hypotheses and theories such as a 3D beam model, von Kármán's strain nonlinearity, Hamilton's principle, and well-established direct and converse FM models, we will derive the constitutive equations for a thick composite beam. Conducting a 3D analysis implies that the strain and strain gradient tensors must be expressed in 3D forms. The inclusion of the term ∂/∂z necessitates the construction of a different model. It should be noted that current commercial finite element codes are not equipped to accurately and adequately handle micro- and nano-sized solids, thus making it impractical to model a flexomagnetic composite structure using these programs. Therefore, we will transform the derived characteristic linear three-dimensional bending equations into a 3D semi-analytical Polynomial domain to obtain numerical results. This study demonstrates the importance of conducting 3D mechanical analyses to explore the coupling effects of multiple physical phenomena in smart structures.

Controlling the Morphology of Tellurene for a High-Performance H2S Chemiresistive Room-Temperature Gas Sensor.

A two-dimensional (2D) van der Waals material composed only of tellurium (Te) atoms-tellurene-is drawing attention because of its high intrinsic electrical conductivity and strong interaction with gas molecules, which could allow the development of high-performance chemiresistive sensors. However, the correlation between the morphologies and gas detection properties of tellurene has not yet been studied in depth, and few reports exist on tellurene-based hydrogen sulfide (H2S) chemiresistive sensors in spite of their strong interaction with H2S molecules. Here, we investigate the morphology-dependent H2S gas detection properties of tellurene synthesized using a hydrothermal method. To tailor the morphologies of tellurene, the molecular weight of the surfactant was controlled, revealing that a 1D or 2D form was synthesized and also accompanied with the high crystallinity. The 1D tellurene-based chemiresistive sensor presented superior H2S detection properties compared to the 2D form, achieving a gas response (Rg/Ra) of ~38, even at room temperature. This outstanding performance was attributed to the high intrinsic electrical conductivity and high specific surface area of the resultant 1D tellurene.

Ion Acoustic Solitary Wave Solutions to mKdV-ZK Model in Homogeneous Magnetized Plasma

In this exploration, we reflect on the wave transmission of three-dimensional (3D) nonlinear electron–positron magnetized plasma, counting both hot as well as cold ion. Treated equation acquiesces to nonlinear-modified KdV-Zakharov–Kuznetsov (mKdV-ZK) dynamical 3D form. The model is integrated by the φ 6 -model expansion scheme and invented few families of ion acoustic solitonic propagation results in term of Jacobi elliptic functions. Various shock waves, bullet like bright soliton, dark soliton, singular soliton, as well as periodic signal solutions, are formed from the Jacobi elliptic solution for different parametric constraints. Some of the solutions are illustrated graphically and analyzed width and height due to change of exist parameters in the solutions. Figures are provided to explain the wave natures and effects of nonlinear and fractional parameters are presented in the same two-dimensional (2D) plots.

Prospects for manufacturing of complex 3D-shaped all-cellulose composites

All-cellulose composites (ACC) have been investigated as a high-strength bio-based alternative to commodity plastics. However, plastic products frequently demand complex 3D geometries as part of their functionality. Hence, a critical factor in the broader application of ACCs is the production of dimensionally-accurate 3D forms. Interestingly, there have been no attempts in the literature to produce 3D geometries based on all-cellulose composites. In the present work, the production of ACCs with 3D geometries is explored for the first time using conventional vacuum and compression moulding procedures. The level of 3D complexity possible in ACCs was examined using a closed mould design that incorporated a range of geometric shapes and angles of varying intricacy. The dimensional accuracy of the final 3D forms was analysed via 3D laser scanning of the surfaces of the as-moulded ACCs. The choice of coagulant type was found to strongly influence the dimensional accuracy of the as-moulded ACCs.

A Multi-Agent System in Education Facility Design

This paper deals with a multi-agent system which supports the designer in solving complex design tasks. The behaviour of design agents is modelled by sets of grammar rules. Each agent uses a graph grammar or a shape grammar and a database of facts concerning the subtask it is responsible for. The course of the design process is determined by the interaction between specialised agents. Space layouts of designs are represented by attributed graphs encoding both topological structures and semantic properties of solutions. The agents work in parallel on the common graph, independently generating layouts of different design components while specified node labels evoke agents using shape grammars. The agents’ cooperation allows them to combine a form-oriented approach with a functional-structural one in the design process, where the agents generate the general 3D form of the object based on design requirements together with the space layout based on the functional aspects of the solution. Based on the given design criteria, the agents search for admissible solutions within the design space that constitutes their operating environment. The proposed approach is illustrated by the example of designing kindergarten facilities.

From blocks to cities: Morphology structure rooted in 3D patterns and forming clusters at the block level

This article proposes a 35D form index system to quantitatively describe the 3D form of urban blocks. Utilizing the T-distributed stochastic neighbor (TSNE) embedding algorithm for cluster analysis, the visually complex and disordered urban 3D texture is translated into distinct form clusters, enabling the recognition of the overall urban form structure from the block perspective. The research methodology includes experiments conducted in the central area of Nanjing and comparative analysis in three neighboring cities: Shanghai, Hangzhou, and Suzhou. Results demonstrate the efficacy of form parameters and cluster analysis in achieving sound recognition. The four cities differ remarkably in the number and distribution structure of clusters. Shanghai has the fewest types of clusters with a compact distribution, Suzhou has the most types with a dispersed distribution, and Hangzhou and Nanjing exhibit similar characteristics, located between Shanghai and Suzhou. Correlation analysis reveals a negative relationship between the number of cluster types and the level of urban socioeconomic development in similar areas. This research implies that governments and urban planners can exploit neighborhood morphological types to devise customized spatial management and renewal strategies. The overall urban structure can be improved by strategically minimizing the quantity and distribution of neighborhood morphological types, fostering socioeconomic development.

Liquid Crystalline and Gel Properties of Luminescent Cyclometalated Palladium Complexes with Benzoylthiourea Ligands.

The design and development of new luminescent metallogels formed by cyclometalated palladium(II) complexes in protic solvents were investigated by a combination of differential scanning calorimetry (DSC), polarized optical microscopy (POM), and rheology. Cyclometalated palladium(II) complexes based on imine ligand and ancillary benzoylthiourea (BTU) ligand showed red emission in solid and gel states. The formation of a lyotropic liquid crystal phase was observed for the complex bearing shorter alkyl groups on the BTU ligand. This complex also behaved as a thermotropic liquid crystal that displays a monotropic smectic A phase (SmA). Dynamic rheology measurements (frequency sweep in the 5-90 °C range) of the 1-decanol solution of palladium(II) complexes highlighted their supramolecular self-association ability to generate 3D networks and form gels as a final result.

Research on 3D Visualization of Real Scene in Subway Engineering Based on 3D Model

As an urban infrastructure project, subway engineering exhibits the characteristics of large scale, trans-regional presence, and complex environmental conditions. The three-dimensional (3D) real scene of subway engineering aims to visually present the project features by creating a virtual environment in the 3D form by integrating numerous geographical scenes and entities. However, existing methods of geometric data integration and model visualization are insufficient for handling the diverse and heterogeneous data types encountered in this process. To address these challenges, this study proposes a framework for real-scene 3D visualization management in subway engineering, establishing a technical process of multi-source data integration for organizing 3D models within the scene, and developing a visualization display strategy that incorporates octree and level of detail principles for multi-scale hierarchical dynamic loading of 3D Scene. To validate the proposed method, a prototype system is developed with Geographic Information System (GIS) and Building Information Modeling (BIM) technology and applied to an actual subway project. The results demonstrate that this method ensures effective integration and management of data, enabling the display of real scenes in an integrated 3D model in a web environment.

Interactive Pedagogical Approach to Teaching in Nigerian Universities: Using Metaverse as Enabling Technology

This paper explored metaverse literature and scholarly works to dissect the concept and potential s of metaverse, being a combination of three-dimensional virtual and real world inhabited by blockchain, artificial intelligence, digital twins, and other cutting -edge intelligent technologies. The study revealed that Metaverse offers a fully immersive educational experience like real-world classroom layouts in 3D form or constructed as partially or fully virtual scenes according to the learning content and the resources can be visualized, especially for the invisible or abstract concepts, items, or events in the physical world. The study further revealed the various challenges confronting the utilization of metaverse technologies in Nigerian Universities which range from inadequate infrastructural facilities, poor research activities, lack of stable electricity, lack of bandwidth and connectivity, inadequate ICT facilities and lack of technically experienced lecturers . The researchers recommended that government should allocate 26 percent of her total budget as recommended by UNESCO to educational sector to enhance the provision of necessary infrastructural facilities needed for the utilization of metaverse technologies in Nigerian Universities. The researchers further recommended that Federal, State government and Universities should undertake in-service training of lecturers through workshops, conferences, seminars and symposia on usage of metaverse, connect the Universities to stable electric grid , employ only competent and qualified lecturers as well as motivate them in terms of salary and other allowances so as to enable them discharged their duties effectively.

Strategies for Improving the Damage Tolerance of Future Composite Materials

Improving the damage tolerance of a composite is identified as a key goal for future developments. A change in emphasis is suggested with a move away from the philosophy of improving performance by increasing the resistance of the laminate to damage formation, which should be accompanied by attempts to control the nature of damage such that energy can be absorbed through cracking in a way that is not deleterious to the final properties of the structure.
 Different strategies are proposed to achieve this, consisting of specific attempts to maximise the resistance of the laminate to damage growth by improving interlaminar toughness, GI (prop) or by introducing new architecture into the composite such that the nature of damage is modified. Examples are provided of the use of interlaminar veils, 3D textile forms and the use of specific fiber hybridisation to facilitate the improved resistance to crack propagation.