Rapid Prototyping Technology Research Articles

Machine learning boosts three-dimensional bioprinting.

Three-dimensional (3D) bioprinting is a computer-controlled technology that combines biological factors and bioinks to print an accurate 3D structure in a layer- by-layer fashion. 3D bioprinting is a new tissue engineering technology based on rapid prototyping and additive manufacturing technology, combined with various disciplines. In addition to the problems in in vitro culture process, the bioprinting procedure is also afflicted with a few issues: (1) difficulty in looking for the appropriate bioink to match the printing parameters to reduce cell damage and mortality; and (2) difficulty in improving the printing accuracy in the printing process. Data- driven machine learning algorithms with powerful predictive capabilities have natural advantages in behavior prediction and new model exploration. Combining machine learning algorithms with 3D bioprinting helps to find more efficient bioinks, determine printing parameters, and detect defects in the printing process. This paper introduces several machine learning algorithms in detail, summarizes the role of machine learning in additive manufacturing applications, and reviews the research progress of the combination of 3D bioprinting and machine learning in recent years, especially the improvement of bioink generation, the optimization of printing parameter, and the detection of printing defect.

Printability assessment of modified filament deposition modelling three dimensional bioprinter printer using polymeric formulations

Three dimensional (3D) bioprinting is a rapid prototyping technology that can be used to accurately position living cells and biomaterials called bioink, to fabricate functional living tissue constructs or organs. The bioink are deposited in 3D in a layer-by-layer manner using a bioprinter. However, commercially available 3D bioprinters are expensive, limiting the widespread adoption of this technology in low-resource laboratories. To overcome this limitation the conventional Filament Deposition Modelling (FDM) 3D printer can be modified to a 3D bioprinter by replacing the print head unit. During the makeover, The device has to perform in its most efficient capacity in synergy with the bioink used. Hence it is essential to check the bio-printabililty of bioink in the modified FDM printer. In this study we created certain specific G-codes for the evaluation of hybrid bioinks and authenticated the printability. This study focuses on quantifying the printability of a hybrid hydrogel composed of sodium salt carboxymethyl cellulose (CMC) and gelatin using a 3D bioprinter based on the RepRap prototyper. The 3D design and slicing parameters were generated using opensource software and manually edited for printability evaluation. The results of these experiments indicate the importance of printability evaluation of custom bioprinters and provide some key aspects of how to modify CAD design parameters for printability evaluation. This approach can also be adopted to evaluate the printability of other hydrogels for bio-printing. The codes are created to evaluate the printability of bioink using FDM modified bioprinters. The printability evaluation is limited to high viscous bioink for extrusion bioprinting. A user friendly, simple G-Codes and methodology for evaluation of printability of bioink using FDM modified bioprinters. To authors knowledge, this is the first report on 3D printability evaluation of bioink using FDM modified bioprinters. The study also fulfills an identified need to study printability of bioink in biofabrication by additive manufacturing.

Rapid tooling: investigation of soft-tooled micro-injection moulding process characteristics using in-line measurements and surface metrology

PurposeThe purpose of this study is to demonstrate and characterise a soft-tooled micro-injection moulding process through in-line measurements and surface metrology using a data-intensive approach.Design/methodology/approachA soft tool for a demonstrator product that mimics the main features of miniature components in medical devices and microsystem components has been designed and fabricated using material jetting technique. The soft tool was then integrated into a mould assembly on the micro-injection moulding machine, and mouldings were made. Sensor and data acquisition devices including thermal imaging and injection pressure sensing have been set up to collect data for each of the prototypes. Off-line dimensional characterisation of the parts and the soft tool have also been carried out to quantify the prototype quality and dimensional changes on the soft tool after the manufacturing cycles.FindingsThe data collection and analysis methods presented here enable the evaluation of the quality of the moulded parts in real-time from in-line measurements. Importantly, it is demonstrated that soft-tool surface temperature difference values can be used as reliable indicators for moulding quality. Reduction in the total volume of the soft-tool moulding cavity was detected and quantified up to 100 cycles. Data collected from in-line monitoring was also used for filling assessment of the soft-tool moulding cavity, providing about 90% accuracy in filling prediction with relatively modest sensors and monitoring technologies.Originality/valueThis work presents a data-intensive approach for the characterisation of soft-tooled micro-injection moulding processes for the first time. The overall results of this study show that the product-focussed data-rich approach presented here proved to be an essential and useful way of exploiting additive manufacturing technologies for soft-tooled rapid prototyping and new product introduction.

Anti-inflammatory and anabolic biphasic scaffold facilitates osteochondral tissue regeneration in osteoarthritic joints

Osteochondral defects (OCD) are common but difficult to heal due to the low intrinsic repair capacity of cartilage and its complex hierarchical structure. In osteoarthritis (OA), OCD become more challenging to repair as both cartilage and subchondral bone regeneration are further impaired due to the arthritic environment. Numerous biomaterials have been developed and tested in osteochondral defects while ignoring the inflammatory environment. To target this challenging underlying pathophysiology, we designed and fabricated a biphasic porous and degradable scaffold incorporating anti-inflammatory and anabolic molecules by low-temperature rapid prototyping technology, and its effects on promoting osteochondral regeneration were evaluated using our well-established OA-OCD rabbit model. The biphasic porous scaffolds consisted of poly lactic-co-glycolic acid (PLGA) with kartogenin (KGN) for cartilage repair and PLGA and β-calcium phosphate (PLGA/β-TCP) with cinnamaldehyde (CIN) for subchondral bone repair. KGN is a molecule for promoting chondrogenesis and CIN is a phytomolecule for enhancing osteogenesis and alleviating inflammation. The biphasic scaffolds PLGA/KGN-PLGA/β-TCP/CIN (PK/PTC) with bio-mimic structure provided stable mechanical properties and exhibited excellent biocompatibility to support cell adhesion, proliferation, migration, and distribution. Furthermore, KGN and CIN within biphasic scaffolds could be released in a controlled and sustained mode, and the biphasic scaffold degraded slowly in vitro. Evaluating the repair of 16-weeks post-implantation into critically sized OA-OCD rabbit models revealed that the biphasic scaffold could promote subchondral bone and cartilage regeneration, as well as reverse subchondral osteosclerosis caused by inflammation in vivo. These findings support the utilization of the PK/PTC scaffold for osteochondral regeneration and provide a promising potential strategy for clinical application for the treatment of patients with OA-OCD.

Three dimensions of printing – deleting pitfalls in endodontic practice

1. Torabi K, Farjood E, Hamedani E. Rapid prototyping technologies and their applications in prosthodontics, a review of literature. J Dent. 2015;16:1–9. Google Scholar

A Review of 3D Polymeric Scaffolds for Bone Tissue Engineering: Principles, Fabrication Techniques, Immunomodulatory Roles, and Challenges.

Over the last few years, biopolymers have attracted great interest in tissue engineering and regenerative medicine due to the great diversity of their chemical, mechanical, and physical properties for the fabrication of 3D scaffolds. This review is devoted to recent advances in synthetic and natural polymeric 3D scaffolds for bone tissue engineering (BTE) and regenerative therapies. The review comprehensively discusses the implications of biological macromolecules, structure, and composition of polymeric scaffolds used in BTE. Various approaches to fabricating 3D BTE scaffolds are discussed, including solvent casting and particle leaching, freeze-drying, thermally induced phase separation, gas foaming, electrospinning, and sol-gel techniques. Rapid prototyping technologies such as stereolithography, fused deposition modeling, selective laser sintering, and 3D bioprinting are also covered. The immunomodulatory roles of polymeric scaffolds utilized for BTE applications are discussed. In addition, the features and challenges of 3D polymer scaffolds fabricated using advanced additive manufacturing technologies (rapid prototyping) are addressed and compared to conventional subtractive manufacturing techniques. Finally, the challenges of applying scaffold-based BTE treatments in practice are discussed in-depth.

Pengaruh Parameter Proses 3D Printing Terhadap Kuat Bentur Menggunakan Fiamen Polycarbonate

The existence of this 3D printing technology in manufacturing has brought big companies to the world of industry. One of the rapid prototyping technologies that are often found in the market today is the FDM type of technology. Fused Deposition Modeling (FDM) technology is a printing technique used to print products using fibrous materials, printed products have ideal geometric characteristics. Impact test is a method used to determine the strength, hardness and ductility of a material. In this impact test, rapid loading is used. The method used is Taguchi and this study aims to obtain optimal process parameters in the impact test. Printing was carried out with a 3D printing machine Creality Ender 3 which printed 81 specimens. Then the impact test was carried out so that the highest average value of the impact test results was in experiment number 27 with a value of 0.00392 joules and for the lowest impact test value was in experiment number 1 with a value of 0.00291 Joules. The method used in this process parameter optimization research is the Taguchi L9 OA method. for the factors used, namely printing speed, infill layer thickness, wall thickness, print temperature. . the results of the research that has been carried out show the optimum parameter values ​​and parameters that influence the impact test successively, namely printing speed (40mm/s), infill layer thickness (0.2mm), wall thickness (2.0mm), print temperature (250 ℃), bed temperature(250℃), infill overlap(30mm), raft extra margin(7.5mm), wall printing speed(22.5mm/s). It was found that the highest average value of the impact test results was in experiment number 2 with a value of 0.031 joules and the lowest impact test value was in experiment number 7 with a value of 0.026 Joules.

Study on Sustainable Development of Carbonate Reservoir Based on 3D Printing Technology

With its abundant reserves in the world, carbonate reservoir has become one of the main targets for future oil and gas development. Accelerating the research and development of carbonate reservoirs is thus significant to enhance the world’s energy supply capacity. However, there have been some problems in the evaluation of carbonate reservoirs for a long time, such as low description accuracy of fractured-vuggy bodies, diverse flow patterns, and difficult reservoir simulation and prediction. Compared with traditional manufacturing methods, 3D printing is an advanced manufacturing technology of rapid prototyping. It has the characteristics of short manufacturing cycle, not limited by the complexity of parts, material saving and energy saving, and thus has unparalleled advantages in reservoir rock analysis. In this paper, the carbonate core of Yingmaili region in Tarim Basin was taken as the research object, and the uniaxial compression mechanical properties of three small cores printed with different materials were designed and tested by using KINGS-600 3D photocuring printer and photosensitive resin materials. After that, UV-9400S white resin with the highest strength is selected as the printing material of the full diameter core model of the karst cave. Combined with the CT scanning of the formed samples, the control accuracy concerning the cave morphology of the 3D printed samples was tested which adequately proves that flow experiments can be carried out with 3D printed core samples. At last, the article also analyzes the shortcomings of 3D printing technology, and points out the direction for its large-scale application in the field of oil and gas exploitation. This study can especially provide a reference for the application of 3D printing technology in the field of carbonate reservoir development, and ultimately promote the sustainable supply of oil and gas resources.

Development and Evaluation of a Low‐Cost LEGO 3D Bioprinter: From Building‐Blocks to Building Blocks of Life

AbstractThe development of low‐cost accessible technologies for rapid prototyping of mechanical components has democratised engineering tools for hobbyists and researchers alike. The development of analogous approaches to fabrication of soft‐matter, and biologically compatible materials containing living cells, is anticipated to be similarly enabling across multiple fields of biological research. LEGO toy construction bricks represent low‐cost, precision engineered, and versatile construction materials for rapid prototyping. This study demonstrates construction of a benchtop LEGO 3D bioprinter for additive layer manufacture of a 3D structure containing viable human skin cells within a hydrogel scaffold. 3D bioprinted structures are formed from the deposition of microfluidically generated bio‐ink droplets containing live keratinocyte skin cells, representing components toward an artificial skin model. Fluid flow rates and printer speed, together with bio‐ink gelation rate, determine droplet packing arrangement in the bioprinted structures. The printing of 3D structures containing multiple bio‐inks is demonstrated and live cells are imaged in the resulting bioprints. Fluid delivery can be achieved using LEGO pumps and readily available, or home‐3D‐printed, microfluidic components, therefore avoiding the need for any specialist microfluidic hardware. Build instructions are described to enable easy uptake, modification and improvement by other laboratories, as well provide an accessible platform for learning and education. Affordable, accessible, and easy to use tools for 3D bioprinting are anticipated to open opportunities for a greater number of research labs to work with 3D cell culture and bio‐printed materials, with bioprinting expected to assist in better understanding of disease, contribute to tissue engineering and repair, and enable personalised medicine through the printing of cultured patient cells. The presented approach is not only an easily accessible laboratory tool for bioprinting, but also provides a learning system for mechanical construction, robotics, coding, microfluidics and cell biology, making it a versatile platform for research, education, and science engagement.

Exploration and Application of Loose Leaf Teaching Material Reverse Engineering and Rapid Prototyping Technology under the Background of "Three Education" Reform

Based on the background of the "three education" reform, this project explores the application of loose leaf teaching materials of Reverse Engineering and Rapid Prototyping Technology, fully implements the National Vocational Education Reform Implementation Plan, closely combines the four in one talent training goal of "values+knowledge+skills+innovation", and aims at the teaching materials in the "three education" reform task. In the classroom construction research of Reverse Engineering and Rapid Prototyping Technology, combined with the specific situation of the professional students and their own teaching experience, this paper puts forward the application and exploration of teaching materials for the course of Reverse Engineering and Rapid Prototyping Technology. In view of the characteristics of vocational education, one is to change the proportion of theory and practice in the content of teaching materials, strengthen the connection with production and life, highlight the integration of theory and practice, and pay attention to the renewal and change of learning methods by technological development. The second is to improve the form of teaching materials, supplement the classical paper teaching materials with loose leaf teaching materials to new technologies and processes, build new teaching materials, and break through the status quo of traditional teaching materials, to build a complete curriculum teaching system by constantly improving the digital and information resources of curriculum teaching. In addition, through the improvement of loose leaf teaching materials and innovative research on the teaching mode of combining online and offline courses, we can achieve complementary advantages and promote the optimization of curriculum teaching.

Research on the Integration and Reform of Ideological and Political Elements in the Teaching of Rapid Prototyping Technology Course

With the continuous development of science and technology, rapid prototyping technology has been widely used in manufacturing industry. However, the teaching of rapid prototyping technology often pays attention to the technology itself and ignores the cultivation of students’ ideological and moral literacy. In order to better cultivate students’ comprehensive quality and sense of social responsibility, this study aims to explore how to integrate ideological and political elements into the teaching of "Rapid Prototyping Technology" to improve students’ ideological and moral quality and comprehensive ability. The results of this study are of great significance for promoting the reform of ideological and political education in the course of rapid prototyping technology, and provide useful reference for relevant teachers and decision makers.

Rapid Prototyping and Tooling Technology to Assist the Development of Low-Cost Dies

This case study aims toward the importance of the application of rapid prototyping and tooling technology in die design and manufacturing. Many conventional machining processes of die manufacturing, including computer numeric control (CNC) machining and electric discharge machining (EDM), are used by the local manufacturers of die, but these processes are time-consuming and expensive. There is a need to explore opportunities to reduce die manufacturing costs. This paper aims to assist the development of low-cost dies through the application of rapid prototyping and tooling technology. For this purpose, solid works software was used to design the die of a 4-hole Lego Block. 3D printing was incorporated in the existing capability of investment casting process for die manufacturing. A proper gating system design consideration was taken into account to ensure the accurate flow of casting material for achieving fine surface finish. From the results, it has been observed that gating system design with four ingates gives the optimum value of surface finish (~3.4156μm). The proposed rapid prototyping and tooling technology makes the practitioners (tool makers) capable of making dies with complex shapes, superior surface finishes, and dimensional accuracy in less or no time.

Reverse Engineering and Rapid Prototyping in the Process of Developing Prototypes of Automotive Parts

The presented article deals with the application of Reverse Engineering and Rapid Prototyp-ing processes in the development process in the automotive industry. In our case, we will focus on the design of the exterior rear view mirror. We obtained the information about the shape and as well as the data used to model the part in a virtual CAD computer environment by scanning it with a Leica laser scanner. The obtained point cloud was imported into CATIA V5 software, which is often used in the automotive industry. In the CATIA software modules, section curves were translated into cloud points. Based on these curves, free shaped surfaces of the mirror body and its holder on the car door were created. After creating the mirror body-mirror mount assembly, print data of these parts were generated for production by Rapid Prototyping technology. The printing method based on ABS material using the FDM (Fused Deposition Modeling) method was chosen.

CUSTOMISED INFILL PATERNS FOR STREGHTENED 3D PARTS

The development of rapid prototyping technologies generates a strong concern for saving all types of materials while maintaining, or even increasing, the strength of 3d printed parts. One way to partially meet this requirement is to make models with a low degree of filling. However, the types of predefined filling structures, defined in the slicing programs, are relatively small in number, being based on repetitive patterns. In this paper it is proposed to make a specimen with a filling structure adapted to the expected stress that appear during operation. Model design can be done in any computer-aided design environment. The deformations of the modified specimen were compared with the deformations of some models with predefined filling structures, under the conditions of maintaining the same loads. This comparison allows to verify the strength of the specimen, under the conditions of using the same volume of material, compared to the models with predefined structure. In addition, conclusions can be drawn regarding the strength of various filling patterns and the time required to print the specimen. The favorable results create the premises of developing an algorithm that can allow the generation of some filling models optimized for different types of loads and eventually the possibility of applying the same concept of custom filling structure for other rapid prototyping technologies.

Finite element analysis of oil palm fiber reinforced thermoplastic composites for fused deposition modeling

Engineers and manufacturers can benefit from finite element analysis (FEA) data of mechanical properties of 3D-printed products to enhance the quality and performance. Fused deposition modelling (FDM) is a filament-based rapid prototyping technology that enables the introduction of novel composite materials as long as they can be produced as feedstock filaments. In prior research, a novel material, oil palm fiber composites filament, was produced for FDM. Then, the tensile and flexural test were conducted according to ASTM 638 and ASTM 730 using universal testing machine. In this paper, the uniaxial tensile test, flexural test, and the construction of a material model for the prediction of the stress–strain response were simulated using nonlinear FEA. The plots of Von Mises stress, resulting displacement, and strain were created. In addition, the derived von Mises plasticity material model and boundary conditions accurately represented the behavior of the specimen under uniaxial tension load, with only minimal differences between actual and theoretical results. The tensile and flexural strengths of oil palm fiber composite (3 wt%) were 33.14 and 33.81 MPa, respectively, according to the results of the FEA simulation. The difference between simulation and experimental error was minor, ranging from 5.4 to 15.2 percent. The aim of this research was to apply non-linear FEA to validate experimental results from tensile and flexural tests of oil palm fiber composites filament, which would be used as a raw material for FDM.

Progress in the application of 3D printing technology in ophthalmology.

Three-dimensional printing (3DP) technology is a rapid prototyping technology that is widely used in the medical field. It can be combined with computer-aided design, material manufacturing, and other technologies to construct medical-related appliances, human implants and even cell-based models or biological tissues. In the field of ophthalmology, the technology can be used to manufacture ocular anatomical models, glasses, intraocular implants, microsurgical instruments, drugs, etc. It can also enable future 'bioprinting', involving the refractive and nervous systems of the eyeball, with excellent development prospects in the field. This review introduces the development of 3DP technology in ophthalmology and discusses its application and potential.

Research on 3D Printing Technology of Polylactic Acid

Additive manufacturing technology(3D printing) as a rapid development of rapid prototyping technology in recent years. However, the surface quality and mechanical properties of the molded parts are worse than those of traditional material reduction manufacturing due to the special bottom-up processing and forming principle. In this paper, the performance of FDM parts is improved by studying the process parameters. According to the actual research situation, this paper selected the filling density, printing speed, printing temperature, stratification direction for experimental research. Through orthogonal test and single factor method, the best strength combination is obtained as filling density 80%, printing speed 35mm/s, printing temperature 195℃. After range analysis, it is found that the filling density has the greatest influence on tensile strength, followed by printing speed and printing temperature. the lamination direction also has a significant influence on tensile strength.

Model-Based Fault Diagnosis of Actuators in Electronically Controlled Air Suspension System

The air suspension adjusts the height of the vehicle body through charging and bleeding air to meet the high performance of the vehicle, which needs a reliable electronic control system. Through fault tree analysis of the electronically controlled air suspension (ECAS) system and considering the correlation between the duty cycle and flow rate of the air spring solenoid valve, the fault model of the solenoid valve is constructed, and the fault diagnosis design method of the ECAS system solenoid valve based on multiple extended Kalman filter banks (EKFs) is proposed. An adaptive threshold is used to realize fault diagnosis, and active fault-tolerant control is carried out based on an analytical model. The real controller based on d2p rapid prototyping technology and the vehicle model based on AMESim are further verified on the hardware-in-the-loop (HiL) simulation test platform and compared with the pure simulation results. The test results show that the fault diagnosis and fault-tolerant control algorithm can work normally in the actual controller, and can effectively realize the fault diagnosis and fault-tolerant control of the actuator in the vehicle ECAS system.

Hybrid Polymer Composites Based on Polystyrene (PS) Used in the Melted and Extruded Manufacturing Technology.

As part of the work, innovative hybrid polymer composites dedicated to rapid prototyping, especially for 3D printing with the melted and extruded manufacturing (MEM) technique, were developed. For this purpose, the influence of modified fillers, such as alumina-modified silica, bentonite modified with quaternary ammonium salt, and lignin/silicon dioxide hybrid filler, on the functional properties of polystyrene-based composites was investigated. The introduced additives were selected to improve the processing properties of polystyrene (PS), in particular its thermal stability, while maintaining good mechanical properties. In the first part of the work, using the proprietary technological line, filaments from unfilled PS and its composites were obtained, which contain modified fillers in the amount of 1.5% to 3.0% by weight. Samples for testing functional properties were obtained by 3D printing in MEM technology and injection technique. The rheological properties-mass melt flow rate (MFR), viscosity, and mechanical properties-are presented in the further part of the work. The size and the respective dispersion in the polystyrene polymer matrix of the fillers used were determined by scanning electron microscopy with energy dispersion spectroscopy (SEM/EDS). The correct dispersion of additives in PS was also confirmed by wide-angle X-ray analysis (WAXS). A significant improvement in the thermal stability of the obtained composites after the introduction of fillers into the polymer matrix was confirmed on the basis of thermogravimetric analysis (TGA). The remaining tests of physicochemical properties, differential scanning calorimetry (DSC), and infrared spectroscopy with Fourier transform (FT-IR) allowed us to state no significant changes in relation to polystyrene. The obtained test results allowed us to conclude that the amount and type of fillers used in the PS polymer matrix significantly affect the performance properties of the tested hybrid composites. The composites obtained as part of the work can be successfully used in rapid prototyping technologies, especially for the production of details originally designed from PS, which are required to have higher thermal stability than is guaranteed only by the polymer matrix.

Membrane Fabrication for Carbon Dioxide Separation: A Critical Review

AbstractMembrane fabrication methods, mechanisms, and modification of membranes for CO2 separation are discussed. Various types of membrane materials with high CO2 separation performance are summarized. Rapid prototyping can achieve precise control of the thickness of membranes and freely design the spatial structure of membranes, which provides a new development direction for material application and process combination. Hence, a critical comparison of membrane fabrication using different methods can provide a comprehensive overview on the potential of the rapid prototyping technology in membrane fabrication. This is important to demonstrate the prospects of the membrane technology development for CO2 separation.