3D Applications Research Articles

The Mechanical and Physical Properties of 3D Printing Filament made from Recycled Polypropylene and Ground Tyre Rubber Treated with Alkali

When molten, used vehicle tyres are unable to decompose or be recycled. Despite global efforts to find new uses for these materials, many worn tyres are still dumped in landfills. Therefore, this study proposes using ground tyre rubber (GTR) as a fill material for recycled polypropylene 3D printing filament. The filament composite’s physical and mechanical properties will be assessed in this investigation. GTR is expected to give the filament elastic characteristics, which could lead to rubber-like filaments. This study filled recycled polypropylene (rPP) polymer matrix composites with GTR to make filament. The mechanical and physical properties of a 3D-printed specimen made from rPP and GTR filament with varying compositions were analysed. Compared to pure rPP, rPP/GTR samples with 3 wt% GTR had a maximum tensile strength of 716.76 MPa. The flexural test findings showed that rPP/GTR with 3 wt% GTR had the highest flexural strength at 80.53 MPa, followed by rPP/1 wt% GTR at 65.38 MPa. In physical tests, the rPP/GTR at 5 wt% GTR had the highest water absorption at 5.41 %, and the wt% of GTR connected directly with water absorption. This study has shown that affordable, environmentally friendly rPP/GTR filaments can be developed with less amount of GTR content (3 wt%) and used for 3D printing applications, helping to lessen the impact of plastic and waste while having valuable mechanical and physical properties that are comparable to those of the pure polypropylene material produced.

Application and prospective of sand-type 3D printing material in rock mechanics: a review

PurposeThis paper aims to investigate the application of 3D printing technology, particularly using sand-type materials, in the creation of artificial rock models for rock mechanics experimentation.Design/methodology/approachUsing a comprehensive analysis, this research explores the utilization of 3D printing technology in rock mechanics. Sand-type materials are specifically investigated for their ability to replicate natural rock characteristics. The methodology involves a review of recent achievements and experimentation in this field.FindingsThe study reveals that sand-type 3D printing materials demonstrate comparable properties to natural rocks, including brittle characteristics, surface roughness, microstructural features and crack propagation patterns.Research limitations/implicationsWhile the research establishes the viability of sand-type 3D printing materials, it acknowledges limitations such as the need for further exploration and validation. Generalizability may be constrained, warranting additional research to address these limitations.Originality/valueThis research contributes insights into the potential application of sand-type 3D printing materials in indoor rock physics experiments. The findings may guide future endeavors in fabricating rock specimens with consistent structures for practical rock mechanics applications.

Effect of κ-carrageenan on physicochemical and 3D printing properties of walnut protein-stabilized emulsion gel

Walnut protein (WP)-stabilized oil-in-water (O/W) emulsion gel can be used to produce food through 3D printing, but there was a problem of poor printing accuracy. We added κ-carrageenan (KG) to enhance the shape retention of corresponding printed products. In this study, the effect of KG on various physicochemical properties of the WP-stabilized O/W emulsion gel was investigated. The rheology results showed that adding KG significantly enhanced the mechanical strength and the viscosity of the produced WP-KG emulsion gel. The Lissajous curves indicated that the response of all samples under 10% low strain was mainly elastic, and the gels with 0.2, 0.3 and 0.4 (w/w) KG had great shear recovery performance against deformation. The increased KG content in the gel reduced the number of pores, promoted emulsions droplet aggregation, reduced crystallinity, and decreased the water-binding ability of the gel. Adding KG to the gel significantly increased its hardness, resilience, and gumminess while reducing its springiness. Various emulsion gels with different KG contents were further used as the bioink for 3D printing. The result suggested that KG improved the printing accuracy and self-supporting ability of 3D-printed products. However, excessive KG (>0.4%, w/w) caused uneven extruded filaments, reduced the adherence between printed layers and decreased printing accuracy. Among various WP-KG emulsion gels, WP-KG0.3 was most appropriate for the 3D printing application.

3D imaging application to the study of the early Neolithic ceramic complex: the decorated pottery of Rio Tana (Abruzzi, Italy)

This study aims to demonstrate the potential of 3D analysis in the study of prehistoric ceramic complexes. Due to the production systems used, prehistoric pottery decorations can vary significantly. Examining the frequency of various decorative methods used at different sites may help identify areas potentially connected to specific traditional elements. However, this is usually a cumbersome and time-consuming task. 3D digital methodologies can bring several advantages in the interpretation of ceramic decoration, providing new tools that can improve analytical skills, speed up the decision process, and support the researcher’s conclusions. This work focuses on the application of these methodologies to the study of decorated ceramics from the Neolithic site of Rio Tana (Abruzzo, central Italy): firstly, a pottery complex from this site has been 3D digitised; then, an interactive and web-based 3D visualisation system has been developed to enable access and study of these digital data. By comparing archaeological data with experimental data, in parallel with the analysis of 3D models’ surfaces, it has been possible to better define the technique employed and quickly identify the type of tool used to create the ceramic decorations. Furthermore, the web-based system made it possible to share and disseminate the digital dataset with the community, creating the conditions to make it easier to compare the frequency of different decoration methods and tools used at Rio Tana with other sites.

Attention 3D U-NET for dose distribution prediction of high-dose-rate brachytherapy of cervical cancer: Direction modulated brachytherapy tandem applicator.

Direction Modulated Brachytherapy (DMBT) enables conformal dose distributions. However, clinicians may face challenges in creating viable treatment plans within a fast-paced clinical setting, especially for a novel technology like DMBT, where cumulative clinical experience is limited. Deep learning-based dose prediction methods have emerged as effective tools for enhancing efficiency. To develop a voxel-wise dose prediction model using an attention-gating mechanism and a 3D UNET for cervical cancer high-dose-rate (HDR) brachytherapy treatment planning with DMBT six-groove tandems with ovoids or ring applicators. A multi-institutional cohort of 122 retrospective clinical HDR brachytherapy plans treated to a prescription dose in the range of 4.8-7.0Gy/fraction was used. A DMBT tandem model was constructed and incorporated onto a research version of BrachyVision Treatment Planning System (BV-TPS) as a 3D solid model applicator and retrospectively re-planned all cases by seasoned experts. Those plans were randomly divided into 64:16:20 as training, validating, and testing cohorts, respectively. Data augmentation was applied to the training and validation sets to increase the size by a factor of 4. An attention-gated 3D UNET architecture model was developed to predict full 3D dose distributions based on high-risk clinical target volume (CTVHR) and organs at risk (OARs) contour information. The model was trained using the mean absolute error loss function, Adam optimization algorithm, a learning rate of 0.001, 250 epochs, and a batch size of eight. In addition, a baseline UNET model was trained similarly for comparison. The model performance was evaluated on the testing dataset by analyzing the outcomes in terms of mean dose values and derived dose-volume-histogram indices from 3D dose distributions and comparing the generated dose distributions against the ground-truth dose distributions using dose statistics and clinically meaningful dosimetric indices. The proposed attention-gated 3D UNET model showed competitive accuracy in predicting 3D dose distributions that closely resemble the ground-truth dose distributions. The average values of the mean absolute errors were 1.82±29.09Gy (vs. 6.41±20.16Gy for a baseline UNET) in CTVHR, 0.89±1.25Gy (vs. 0.94±3.96Gy for a baseline UNET) in the bladder, 0.33±0.67Gy (vs. 0.53±1.66Gy for a baseline UNET) in the rectum, and 0.55±1.57Gy (vs. 0.76±2.89Gy for a baseline UNET) in the sigmoid. The results showed that the mean absolute error (MAE) for the bladder, rectum, and sigmoid were 0.22±1.22Gy (3.62%) (p=0.015), 0.21±1.06Gy (2.20%) (p=0.172), and -0.03±0.54Gy (1.13%) (p=0.774), respectively. The MAE for D90, V100%, and V150% of the CTVHR were 0.46±2.44Gy (8.14%) (p=0.018), 0.57±11.25% (5.23%) (p=0.283), and -0.43±19.36% (4.62%) (p=0.190), respectively. The proposed model needs less than 5 s to predict a full 3D dose distribution of 64×64×64 voxels for any new patient plan, thus making it sufficient for near real-time applications and aiding with decision-making in the clinic. Attention gated 3D-UNET model demonstrated a capability in predicting voxel-wise dose prediction, in comparison to 3D UNET, for DMBT intracavitary brachytherapy planning. The proposed model could be used to obtain dose distributions for near real-time decision-making before DMBT planning and quality assurance. This will guide future automated planning, making the workflow more efficient and clinically viable.

59‐4: Towards Real‐time 3D Computer‐Generated Holography with Inverse Neural Network for Near‐eye Displays

Holography plays a vital role in the advancement of virtual reality (VR) and augmented reality (AR) display technologies. Its ability to create realistic three‐dimensional (3D) imagery is crucial for providing immersive experiences to users. However, existing computer‐generated holography (CGH) algorithms used in these technologies are either slow or not 3D‐compatible. This article explores four inverse neural network architectures to overcome these issues for real time and 3D applications.

Cone Beam Computed Tomography: An essential ally to Undergraduates in their Dental Practice

Cone beam computed tomography (CBCT) has developed into a crucial technique in contemporary dentistry, enabling dentists to examine the interaction between teeth and the tissues around them. The use of CBCT, improves the precision of diagnoses, planning, and follow-up in difficult patients. In order to give clinically valuable information based on a set of volumetric data, image post-processing and subsequent visualization rely on software for 3D navigation and application of indexation techniques. Diagnostic quality relies heavily on image post-processing, and a variety of methods have been used, including multiplanar reformations, maximum intensity projection, and volume rendering. CBCT is expected to be used routinely in most offices during the next few decades and shall be considered the "gold standard" for imaging of the oral and maxillofacial region.

Development and Application of 3D Printing Manufacturing Technology in Intelligent Vehicle Design

With the rapid development of intelligent vehicle technology, traditional vehicle design and manufacturing methods are facing many challenges. Traditional vehicle design and manufacturing methods have problems such as high cost, long development cycle and lack of personalized design. This paper took advantage of the high degree of flexibility, rapid customization and cost savings of 3D printing technology, which can provide entirely new solutions for intelligent vehicle design. This paper mainly analyzed the application of three-dimensional (3D) printing and manufacturing technology in intelligent vehicle design. In intelligent vehicle design, 3D printing can carry out 3D printed body structure design to make parts lightweight. The displacement sensor in the intelligent sensor can measure the displacement, deformation and vibration of the body components, and detect whether the body structure exceeds the safety range, which can provide safety feedback to the owner. 3D printing technology has been involved in automotive dashboard, interior design and customization. In this paper, the effects of vehicles designed under traditional methods and vehicles designed under 3D printing manufacturing technology were compared. The research and development cycle of class A, Class B, Class C and Class D in brand 1 under traditional manufacturing was 3.85 years, 3.13 years, 4.27 years and 4.32 years respectively. The R&D (research and development) cycle of grade A, B, C and D in brand 1 under 3D printing technology was 2.43 years, 2.05 years, 1.64 years and 1.73 years respectively. Under the traditional method, the average R&D cost of different levels of vehicles in brand 1, brand 2 and brand 3 was 191,000 yuan, 20900 yuan and 227,200 yuan respectively. Under 3D printing technology, the average R&D cost of different levels of vehicles in brand 1, brand 2 and brand 3 was 132,600 yuan, 145,300 yuan and 157,500 yuan respectively. The results of this paper emphasize that the application of 3D printing manufacturing technology shortens the development cycle of intelligent vehicles, reduces the development cost, and can be customized, which can be more in line with the needs of users.

Physical model test and application of 3D printing rock-like specimens to laminated rock tunnels

Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels, resulting in steel arch distortion and secondary lining cracking. In this study, a servo biaxial testing system was employed to conduct physical modeling tests on layered rock tunnels with bedding planes of varying dip angles. The influence of structural anisotropy in layered rocks on the micro displacement and strain field of surrounding rocks was analyzed using digital image correlation (DIC) technology. The spatiotemporal evolution of non-uniform deformation of surrounding rocks was investigated, and numerical simulation was performed to verify the experimental results. The findings indicate that the displacement and strain field of the surrounding layered rocks are all maximized at the horizontal bedding planes and decrease linearly with the increasing dip angle. The failure of the layered surrounding rock with different dip angles occurs and extends along the bedding planes. Compressive strain failure occurs after excavation under high horizontal stress. This study provides significant theoretical support for the analysis, prediction, and control of non-uniform deformation of tunnel surrounding rocks.

Application of 3D Printing Positioning Technology in Parasagittal Meningioma Surgery: A Single-center Retrospective Study

To assess the utility of 3D printing positioning technology for resection of parasagittal meningioma. Information related to clinical history, application of 3D printing positioning technology, neuroimaging, surgical-related information, and postoperative hospital days of consecutive patients with parasagittal meningioma treated between January 2020 and December 2022 were retrospectively collected. Patients were divided into 2 groups based on whether the 3D printing positioning technology was applied. The values between groups were statistically compared. A total of 41 patients were enrolled. In cases using 3D printing positioning technology (14 patients), the location of craniotomy was much better and the postoperative hospital stay was much shorter. The application of 3D printing positioning technology in parasagittal meningioma surgery could improve the location of craniotomy, and reduce the postoperative hospital stay. It is a low-cost positioning technology, and has the potential to be applied to other superficial intracranial tumors.

3D ED/MicroED entering a new era.

Aragon et al. [Acta Cryst. (2024), C80, 179-189], by reporting the discussion and the final conclusions of a round table held during a symposium at the National Center for CryoEM Access and Training, well describe all the advances that have been made for the application of 3D ED/MicroED to pharmaceutical and macromolecular nanocrystals and propose possible future scenarios.

Nano-fly ash and clay for 3D-Printing concrete buildings: A fundamental study of rheological, mechanical and microstructural properties

Three-dimensional printing concrete (3DPC) represents a recent innovation in the construction and building research sector and novel approach to building techniques. The focus of this study is to develop an environmentally sustainable cementitious composite optimized for 3D printing applications. The research involved preparing 3D printing mixtures that comprised of 50 % Portland Cement (PC), 50 % Colorobia Clay (CC), and varying contents (0 % 5 %, 10 %, and 15 % by weight of cement) of Nano-Fly Ash (N-FA) under standardized printing parameters. The fresh mixture's properties have been evaluated and the mechanical and microstructural properties of the printed samples were assessed, subsequently. The findings demonstrated that incorporating N-FA into the cementitious mixes enhanced their flowability and workability. Specifically, the mix containing a low N-FA concentration of 5 wt% exhibited superior compressive strength relative to the other formulations. Additionally, flexural strength assessments indicated a minimum increase of 39.4 % across all mixes compared to the control 3D-printed mixture. Microstructural investigations by SEM imaging validated the anticipated formation of hydration products, namely calcium-silicate-hydrate (CSH) and ettringite, facilitated by the synergy between clay and fly ash. The t-statistical analysis further corroborated that the inclusion of N-FA significantly bolstered the strength attributes of the mixes designated for 3D printing. In conclusion, this study underscored the efficacy of integrating clay as a sustainable construction material within 3D printing applications. The utilization of clay-cement mixes, augmented with N-FA, emerged as a viable strategy to enhance the sustainability and reduce the carbon footprint of construction practices.

7 Tesla magnetic resonance spectroscopic imaging predicting IDH status and glioma grading.

With the application of high-resolution 3D 7 Tesla Magnetic Resonance Spectroscopy Imaging (MRSI) in high-grade gliomas, we previously identified intratumoral metabolic heterogeneities. In this study, we evaluated the potential of 3D 7T-MRSI for the preoperative noninvasive classification of glioma grade and isocitratedehydrogenase (IDH) status. We demonstrated that IDH mutation and glioma grade are detectable by ultra-high field (UHF) MRI. This technique might potentially optimize the perioperative management of glioma patients. We prospectively included 36 patients with WHO 2021 grade 2-4 gliomas (20 IDH mutated, 16 IDH wildtype). Our 7T 3D MRSI sequence provided high-resolution metabolic maps (e.g., choline, creatine, glutamine, and glycine) of these patients' brains. We employed multivariate random forest and support vector machine models to voxels within a tumor segmentation, for classification of glioma grade and IDH mutation status. Random forest analysis yielded an area under the curve (AUC) of 0.86 for multivariate IDH classification based on metabolic ratios. We distinguished high- and low-grade tumors by total choline (tCho) / total N-acetyl-aspartate (tNAA) ratio difference, yielding an AUC of 0.99. Tumor categorization based on other measured metabolic ratios provided comparable accuracy. We successfully classified IDH mutation status and high- versus low-grade gliomas preoperatively based on 7T MRSI and clinical tumor segmentation. With this approach, we demonstrated imaging based tumor marker predictions at least as accurate as comparable studies, highlighting the potential application of MRSI for pre-operative tumor classifications.

Commentary on the application of 3D printing custom-made implants for chest wall/sternal reconstruction.

Commentary on the application of 3D printing custom-made implants for chest wall/sternal reconstruction.

Ultrasound treatment improved the physicochemical properties of pea protein with pectin ink used for 3D printing

Pectin, as a gelling agent enhancer, is capable of augmenting the strength of plant protein gels; however, their direct blending often results in insignificant crosslinking efficiency. The application of ultrasonication has been found to effectively promote crosslinking interactions between pectin and plant proteins. This study primarily probes into the physicochemical impacts on the pea protein system instigated by ultrasonicated apple pectin (AP), citrus pectin (CP), and high methoxyl pectin (HM) variances. It has been revealed that the incorporation of pectin, subsequent to ultrasonication, ameliorates the textural and rheological traits of the pea protein matrix. Nevertheless, the introduction of high methoxyl pectin excessively enhances these identical properties, rendering it unsuitable for use in food development and three-dimensional (3D) printing technologies. Under an ultrasound power setting of 390 W, the citrus pectin variant outperforms other variants with its superior hardness, elasticity, and viscoelasticity, thereby significantly bolstering the self-supporting capability and malleability of the pea protein system for potential utilization in 3D printing applications. In conclusion, the ultrasonically treated pectin-pea protein amalgam optimizes the physicochemical attributes of the pea protein system, contributing to the stability enhancement of 3D printed products.

A short banana fiber—PLA filament for 3D printing: Development and characterization

AbstractThis study aims to develop a 3D printable composite filament using short banana fiber and polylactic acid (PLA). The filament was acquired through a single screw extruder, employing various blending techniques. Various fiber loadings were examined, impacting PLA's mechanical, thermal, and printability properties. The results revealed altered mechanical characteristics, with reduced tensile and flexural properties compared with pure PLA. However, these values are at an acceptable level for non‐structural applications. Compared with previous works, the filament developed in the present work is found out to be second strongest among the cellulose fiber‐reinforced PLA filaments. 3D printing with the composite filament encountered no significant issues. A modified mixing method improved mechanical characteristics, although 3D‐printed samples showed deteriorated mechanical characteristics due to poor interfacial bonding. This research introduces an environmentally viable strategy for advancing 3D printing technology by integrating banana fibers into PLA filament. The proposed strategy can be effectively utilized in making cellulose/PLA filaments for 3D printing applications. This innovative approach preserves PLA's natural biodegradability while carefully managing the integration of banana fibers and their potential effects on mechanical properties.Highlights Fiber loading influences mechanical, with minimal impact on thermal properties. Solution casting improved fiber/matrix bonding and filler homogeneity. Plasticizing effect reduces the tensile strength. Modified mixing resulted in even filament diameter and improved tensile properties.

An efficient multi-field dynamic model for 3D wave propagation in saturated anisotropic porous media

An efficient multi–field coupled dynamic model for saturated anisotropic porous materials is proposed here. The mathematical formulation of the dynamic deformation–diffusion problem is developed starting from the mixture theory and the definition of the effective stress for anisotropic poro–elasticity, taking into account also the fluid phase compressibility and anisotropic permeability. The effective stress principle is properly extended through the Biot tensor to predict the coupling between the shear stress of the solid skeleton and the pore fluid pressure. Numerical solution of the coupled problem is obtained by inf-sup stable Finite Element spaces. A fundamental issue for the computational efficiency of the coupled model is the numerical solution of the resulting large–size and non–symmetric discrete problem. In this work, we develop a fully implicit monolithic solver based on the Bi–Conjugate Gradient Stabilized (Bi-CGStab) algorithm accelerated via an ad–hoc Multi–Physics Reduction (MPR) preconditioning technique. The proposed advances are implemented in the 3D GeoMatFem research code and several numerical analyses are performed to test the potential and computational efficiency of the proposed tool. In particular, we focus on 3D wave propagation applications in fully saturated single and multi-layered anisotropic media. Numerical results show that our implementation is able to identify the shear wave splitting phenomenon due to the different degree of material symmetry between the solid phase and the whole porous material.

Visible Korean based on true color sectioned images for making realistic digital human, twenty years' record: a review.

Visible Korean (VK) consists of two-dimensional (2D) images and three-dimensional (3D) models. The VK is used in various educational tools and research sources for anatomy. In this paper, we report on the records of the VK over 20years. Research papers related to Visible Korean were reviewed. Through this report of VK records, we highlighted the essential points for making true color and ultra-high-resolution sectioned images of human and animal bodies, for making various 2D and 3D applications from the sectioned images, and for good use of the sectioned images and their applications. In this metaverse age that various virtual environments are required in medical education and research, the VK dataset meets the reality of virtual human models as fundamental data owing to the actual color and high resolution of the VK dataset.

Utilization of Silica Filler as Reinforcement Material of Polylactic Acid (PLA) in 3D Printing Applications: Thermal, Rheological, and Mechanical Performance.

Glass was introduced as an additive to filaments used for the manufacturing of composite materials, employed by Additive Manufacturing applications. Glass accounts for a large waste electric and electronic equipment (WEEE) percentage, and its recovery and recycling can lead to the production of sustainable composite materials. In this work, poly(lactic acid) (PLA)/commercially available silicon oxide composite filaments were manufactured and their structural, thermal, rheological, and mechanical properties were assessed. Scanning Electron Microscopy confirmed the 1:2 ratio of silicon: oxygen, along with the relatively low adhesion between the filler and the matrix. Differential Scanning Calorimetry presented steady glass transition and melting temperatures of composites, whereas a crystallization temperature of 10% wt. and a crystallinity of 15% wt. composite slightly increased. Rheological analysis showcased that the viscosity of the composite filaments decreased compared to PLA (10-100 compared to 300-400 Pa·s), with a more shear-thinning behavior. Dynamic mechanical analysis exhibited increased elastic, flexural moduli, and flexural strength of composites (up to 16, 23, and 11%, respectively), whereas tensile strength and elongation decreased. The affordability of raw materials (with the future introduction of recycled ones) and the minimal processing steps can lead to the potential scaling up of the study.

Construction of high-performance and sustainable polylactic acid composites for 3D printing applications with plasticizer

Polylactic acid (PLA) attains much attention because of its biodegradability, biocompatibility, and high strength, but its further application was remarkably hindered by its brittleness. In order to improve the toughness of PLA, a biodegradable composite was prepared by blending ductile polycaprolactone (PCL), stiff microcrystalline cellulose (MCC), and green plasticizer tributyl citrate (TBC) with PLA by melting extrusion. The physicochemical properties and microstructure of PLA composites were thoroughly investigated using FTIR, TGA, DSC, XRD, melting rheology, optical transmittance, 3d printing, tensile tests, and SEM. The tensile tests results show that introduction of TBC exhibited a remarkable improvement effect in the elongation at break of PLA/PCL/MCC (PPM) composite, increasing from 2.9 % of PPM to up to 30 % of PPM/6TBC and PPM/8TBC. Noticeably, the strength of PPM/TBC composites (at least 33.1 MPa) was enhanced compared with that of PPM (28.2 MPa). The plasticization of TBC, enhancing the compatibility of composites, and reinforcing effect of MCC were identified as pivotal factors in toughening and reinforcing PLA. Furthermore, it is observed that the incorporation of TBC contributed to enhanced thermal stability, crystallinity, and rheology property of composites. This research supplies a novel approach to bolstering the toughness of PLA and broaden its potential applications.