Rapid Prototyping Method Research Articles

Development and mechanical properties of nano SiO2 modified photosensitive resin for high-strength and high-brittleness 3D printing in rock reconstruction

3D printing technology, as a rapid prototyping method, can accurately reconstruct the internal structural characteristics of samples, making it highly promising for rock engineering applications. However, current 3D printing materials used to reconstruct rocks suffer from low strength and high ductility, which is inconsistent with the high strength and brittleness of natural rocks. This paper explores the use of silane coupling agents KH550 (γ-aminopropyl triethoxysilane) and KH570 (γ-methacryloxypropyl trimethoxysilane) to modify nano SiO2 powder. Through sample preparation and uniaxial compression tests, the mechanical properties and failure characteristics of the modified nano SiO2 powder were analyzed. The results indicate that, using the preparation method with a mass ratio of E-44 epoxy resin, KH550 modified nano SiO2 powder, and 593 curing agent at 80:40:26, the samples achieved an uniaxial compressive strength of up to 30.55 MPa without enhanced brittle post-processing. The failure characteristics exhibited significant axial tensile damage. Additionally, combining CT scanning technology demonstrated that the structural and mechanical properties of the samples can be effectively reproduced. Therefore, the 3D printing materials discussed in this paper provide a viable reference for accurately reconstructing high-strength and high-brittleness rock masses.

Evaluation of Material Extrusion Printed PEEK Mold Inserts for Usage in Ceramic Injection Molding

The rapid tooling of mold inserts for injection molding allows for very fast product development, as well as a highly customized design. For this, a combination of rapid prototyping methods with suitable polymer materials, like the high-performance thermoplastic polymer polyetheretherketone (PEEK), should be applied. As a drawback, a huge processing temperature beyond 400 °C is necessary for material extrusion (MEX)-based 3D printing; here, Fused Filament Fabrication (FFF) requires a more sophisticated printing parameter investigation. In this work, suitable MEX printing strategies, covering printing parameters like printing temperature and speed, for the realization of two different mold insert surface geometries were evaluated, and the resulting print quality was inspected. As a proof of concept, ceramic injection molding was used for replication. Under consideration of the two different test structures, the ceramic feedstock could be replicated successfully and to an acceptable quality without significant mold insert deterioration.

MODELLING AND 3D-PRINTING OF BEVEL GEAR

Bevel gear have teeth cut on conical blanks. The gear pair is used to connect non-parallel intersecting shafts for motor transmissions, differential drives and mechanical instruments. Bevel gears are used for transmission of power between axles in rear wheel of vehicle will be modelled by using solid works. Shaping, Casting and Grinding are the traditional methods of manufacturing of bevel gear which are time consuming, and increased in production cost. To overcome this, new method such as rapid prototyping method of manufacturing is used which offers the potential for faster and more cost-effective manufacturing with ability to customize the design and improve performance. In this project, the Bevel Gear is designed using solid works by ensuring that the gear's dimensions and tolerances are appropriate for the 3D printing process being used and then the Bevel Gear is printed using the 3D- Printer. Keywords: Bevel Gear, 3D Printing,Rapid Prototyping, Design

Compressing of experimental and simulated results of electron beam interaction with FFF-printed samples

One of the important parameters characterizing the interaction of electron beams with matter is the depth dose distribution. To develop a new approach for shaping electron beams using specially created materials suitable for the manufacture of complex 3D-printed devices, it is necessary to analyze the features of ionizing radiation propagation. In this work, numerical simulations and experimental studies of the interaction between electron beams and plastic materials weighted with metallic impurities of different concentrations, suitable for fabricating samples using the rapid prototyping method, were carried out. Sets of plates made from the investigated plastics were created using the fused filament fabrication (FFF) technique. Since the FFF sample fabrication process involves forming objects from a thermoplastic mass through layer-by-layer alignment, a distinctive feature of the printed samples is their lower actual density compared to the density of the material (filament) from which they are made. Taking this fact into account, the actual density of the polymer plates was calculated. Based on this data, numerical models of the plastic materials weighted with metallic impurities were developed, and virtual models of the experimental setup were created to calculate the electron beam depth dose distributions in the materials. In the next step of the investigation, experimental studies were performed using electron beams with energies of 6 and 10 MeV. Pre-calibrated GafChromic EBT3 dosimetry films were used as detectors to obtain the experimental data on the electron beam depth dose distributions in the materials under consideration. It was observed that with an increasing concentration of metal impurities in the plastic base, the depth dose distribution moves into smaller thicknesses. It was observed that the simulation and experimental results are in good agreement.

Numerical Modeling and Analysis of Transient and Three-Dimensional Heat Transfer in 3D Printing via Fused-Deposition Modeling (FDM)

Fused-Deposition Modeling (FDM) is a commonly used 3D printing method for rapid prototyping and the fabrication of plastic components. The history of temperature variation during the FDM process plays a crucial role in the degree of bonding between layers. This study presents research on the thermal analysis of the 3D printing process using a developed simulation code. The code employs numerical discretization methods with an implicit scheme and an effective heat transfer coefficient for cooling. The computational model is validated by comparing the results with analytical solutions, demonstrating an agreement of more than 99%. The code is then utilized to perform thermal analyses for the 3D printing process. Interlayer and intralayer reheating effects, sensitivity to printing parameters, and realistic printing patterns are investigated. It is shown that concentric and zigzag paths yield similar peaks at different time intervals. Nodal temperatures can fall below the glass transition temperature (Tg) during the printing process, especially at the outer nodes of the domain and under conditions where the cooling period is longer and the printed volume per unit time is smaller. The article suggests future work to calculate welding time at different conditions and locations for the estimation of the degree of bonding.

Controllable Multimodal Actuation in Fully Printed Ultrathin Micro-Patterned Electrochemical Actuators.

Submillimeter or micrometer scale electrically controlled soft actuators have immense potential in microrobotics, haptics, and biomedical applications. However, the fabrication of miniaturized and micropatterned open-air soft actuators has remained challenging. In this study, we demonstrate the microfabrication of trilayer electrochemical actuators (ECAs) through aerosol jet printing (AJP), a rapid prototyping method with a 10 μm lateral resolution. We make fully printed 1000 × 5000 × 12 μm3 ultrathin ECAs, each of which comprises a Nafion electrolyte layer sandwiched between two poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrode layers. The ECAs actuate due to the electric-field-driven migration of hydrated protons. Due to the thinness that gives rise to a low proton transport length and a low flexural rigidity, the printed ECAs can operate under low voltages (∼0.5 V) and have a relatively fast response (∼seconds). We print all the components of an actuator that consists of two individually controlled submillimeter segments and demonstrate its multimodal actuation. The convenience, versatility, rapidity, and low cost of our microfabrication strategy promise future developments in integrating arrays of intricately patterned individually controlled soft microactuators on compact stretchable electronic circuits.

Prototyping of rotating packed bed structural internals

A rapid prototyping method was developed for quick and inexpensive design of various geometrical solutions for rotating packed bed internals. Sixteen geometries were designed with the use of 3D modeling software and subsequently 3D-printed, if possible. The printed packings were tested for dry pressure drop to reject the ones generating too high air flow resistance. Eventually, the packings were tested for wet pressure drop and effective mass transfer area generated in specified conditions. An evaluation method was designed to compare the results from the different packings and determine the geometry most suited for the absorption process.

Development of a direct PMMA-PCB bonding method for low cost and rapid prototyping of microfluidic-based gas analysers.

Rapid prototyping of microfluidic devices requires low cost materials and simple fabrication methods. PMMA and PCB have been used separately for the fabrication of microfluidic devices in a wide range of applications. Although the combined use of PMMA and PCB can have considerable merits, few works have been reported on the direct bonding of these materials. In this work we have investigated the fabrication of microfluidic devices using PMMA and PCB for the analysis of gaseous samples. In order to yield a reliable direct bonding method, four parameters including temperature, pressure, solvent and patterned interface material were experimentally investigated. Results of testing various prototypes showed that a patterned interface of concentric rectangular copper rings exposed to solvent at room temperature and under moderate pressure provided better adhesion strength, sealing and durability. After successful development of the PMMA-PCB direct bonding process, sample prototypes were designed and fabricated to practically assess the combined advantages of two materials. Presented concepts include implementation of heater on a PCB, array of gas sensors coupled with microchannels, serpentine microchannel and fast evaporation of liquid sample using an SMD resistor. It has been shown that advantages of utilizing PMMA such as fabricating the channel easily and with low cost, can be combined with benefits of a PCB including simple sensor installation and the use of copper tracks and electronic components for gas flow modulation. Moreover, it is possible to implement channel, circuit and other electronic components such as microprocessors on a single device.

Fused Deposition Modelling (FDM) of Thermoplastic-Based Filaments: Process and Rheological Properties-An Overview.

The fused deposition modeling (FDM) process, an extrusion-based 3D printing technology, enables the manufacture of complex geometrical elements. This technology employs diverse materials, including thermoplastic polymers and composites as well as recycled resins to encourage sustainable growth. FDM is used in a variety of industrial fields, including automotive, biomedical, and textiles, as a rapid prototyping method to reduce costs and shorten production time, or to develop items with detailed designs and high precision. The main phases of this technology include the feeding of solid filament into a molten chamber, capillary flow of a non-Newtonian fluid through a nozzle, layer deposition on the support base, and layer-to-layer adhesion. The viscoelastic properties of processed materials are essential in each of the FDM steps: (i) predicting the printability of the melted material during FDM extrusion and ensuring a continuous flow across the nozzle; (ii) controlling the deposition process of the molten filament on the print bed and avoiding fast material leakage and loss of precision in the molded part; and (iii) ensuring layer adhesion in the subsequent consolidation phase. Regarding this framework, this work aimed to collect knowledge on FDM extrusion and on different types of rheological properties in order to forecast the performance of thermoplastics.

STUDY OF THE INFLUENCE OF TOOL GEOMETRY AND CUTTING MODES ON THE ACCURACY OF PROCESSING PARTS OBTAINED BY FDM PRINTING

FDM printing (rapid prototyping) is a production process during which you can quickly obtain parts with high geometric complexity, given dimensions and with low energy consumption. From the early stages, 3D printing was identified as a method of rapid prototyping of parts that have a high level of complexity and their manufacture by traditional methods (for example, mechanical processing on CNC machines) is impossible. Despite the advantages that additive manufacturing offers, it has not yet been incorporated into industrial mass production lines as an alternative to traditional technologies, due to the long manufacturing time of parts and the lack of repeatability. In some cases this may not be a serious problem, but in some industrial applications where high precision parts are required, there are limitations due to the surface roughness of the outer layer and the accuracy requirements. To eliminate these shortcomings, an additional processing process is required. The purpose of this study is to determine the most optimal parameters of the cutting tool and cutting modes (spindle rotation frequency, feed rate, depth of cut, diameter of the end mill, geometric parameters of the cutting edge) for mechanical processing of parts obtained by FDM printing from CoPET (PETg) plastic in order to obtain the specified parameters accuracy and surface roughness. The article describes the study of the work of four types of end mills, which differ in the material of the cutting part, geometry, number of cutting teeth, coating. A rectangular prism printed from CoPET plastic, without internal voids, 100% filling, was selected as a blank. Processing was carried out on a MIKRON WF-2 vertical milling machine. For end mills, the cutting process was investigated with two different strategies: milling of a closed groove over the entire working width of the mill; milling of an open groove with the side surface of the cutter. The suitability for effective processing of each type of tool is evaluated. Results were recorded and evaluated using an optical electron microscope.

Quasi-static simulation and fatigue life estimation of fused filament fabrication of polylactic acid specimens using finite element method

The additive manufacturing (AM) technique has recently attracted more attention in rapid prototyping methods due to its unprecedented performance in engineering applications. Fused filament fabrication (FFF) is the most common technique to manufacture sophisticated engineering components by depositing the polymeric material layer by layer. Since the produced materials exhibit different mechanical behaviors, it is required to perform adequate mechanical tests and engineering analysis to attain a product with an acceptable performance under the designed loading conditions. This research deals with a series of tests to achieve the mechanical characteristics of the FFF-made samples printed in different raster orientations. Due to the high level of anisotropy achieved compared to using conventional manufacturing techniques, the effects of printing directions should be studied. In this study, the mechanical properties of FFF Polylactic acid (PLA) specimens, e.g., tensile and fatigue tests were investigated experimentally. Then, the finite element (FE) model for estimating the fatigue behavior of notched samples was developed. To do so, two specimen sets, including unidirectional and double-directional (cross) samples were prepared for experiments. Tensile test results show that in specimens with parallel loading direction and raster orientation, can sustain higher load; however, ultimate strength values in the specimens with perpendicular raster orientation to the loading direction were reduced by 18 %. Furthermore, the strain-life diagrams were obtained through the pure bending fatigue tests, for three specimen sets (unnotched, single-notched, and double-notched) fabricated with a ± 45° raster orientation. The fatigue life of the notched samples was predicted using the FE model and the Coffin-Monson equation. Comparing the experimental and predicted results shows that a good agreement exists between the experimental data and numerical results.

Engineering Biosensors and Biomedical Detection Devices from 3D-Printed Technology

Limitation of 3D construction ability, complex preparation processes and developing customer demands have promoted people to find low-cost, rapid prototyping, and simple operation methods to produce novel functional devices in the near future. Among various techniques, 3D-printed technology is a promising candidate for the fabrication of biosensors and biomedical detection devices with a wide variety of potential applications. This review offers four important 3D printing techniques for biosensors and biomedical detection devices and their applications. The principle and printing process of 3D-printed technologies will be generalized, and the printing performance of many 3D printers will be compared. Despite the resolution restrictions of 3D-printed, these technologies have already shown promising applications in many biosensors and biomedical detection devices, such as 3D-printed microfluidic devices, 3D-printed optical devices, 3D-printed electrochemical devices, and 3D-printed integrated devices. Some of the most representative examples will also be discussed here, demonstrating that 3D-printed technology can rationally design biosensors and biomedical detection devices and achieve important applications in microfluidic, optical, electrochemical, and integrated devices.

Possibilities of Using Selected Additive Methods for the Production of Polymer Harmonic Drive Prototypes.

This article includes an analysis of the possibility of using polymer materials for the production of harmonic drive. The use of additive methods greatly eases and accelerates the manufacturing of the flexspline. In the case of gears made of polymeric materials using rapid prototyping (RP) methods, the problem is often with their mechanical strength. In a harmonic drive, the wheel is uniquely exposed to damage, because during work, it deforms and is additionally loaded with torque. Therefore, numerical calculations were conducted using the finite element method (FEM) in the Abaqus program. As a result, information was obtained on the distribution of stresses in the flexspline and their maximum values. On this basis, it was possible to determine whether a flexspline made of specific polymers could be used in commercial harmonic drives or whether they were only adequate for the production of prototypes.

Effect of nanosized carbon black content on the microstructure, thermal stability, and mechanical properties of 3D printed poly urethane acrylate

The stereolithography method (SLA) is a rapid prototyping method, which can produce complex geometric shapes within the shortest time as compared to conventional manufacturing. The strength of the samples printed via this method is a significant problem for its wide application. Adding an additive can improve the photopolymer substrate properties. In this research, carbon black nanoparticles at 0.1, 0.3, 0.5, and 1 wt% were dispersed inside a urethane acrylate photopolymer using a mechanical stirrer. The nanocomposites were printed in a stereolithography device with a suitable viscosity. The results indicated that the nanocomposite sample containing 0.1 wt% carbon black showed a tensile strength of 16 MPa, and the virgin resin sample revealed a strength of 8 MPa. Elongation to break the pure resin and nanocomposite containing 0.1 wt% of carbon black was 6.36 and 7.17, respectively. Also, the hardness of the samples increased with the elevation of the carbon black content; in the presence of 0.3 and 0.5 % of carbon black, the sample hardness increased from 79 to 83 Shore D as compared to the pure sample. The thermal stability or degradation temperature increased from 316 °C for the pure resin to 343 °C for the nanocomposite containing 0.1 % carbon black; with a further elevation of the carbon black content, the degradation temperature diminished.

Experimental study of manufacturing of human mandible using fusion deposit modeling (rapid prototyping)

Rapid prototyping method is used, for the manufacture of human mandible for replacement for accident victims. Rapid prototyping will make the manufacture of implants much easier and more exact than conventional methods such as titanium implant manufacturing in Alveolar ridge augmentation. After performing the necessary tests, the material selected for usage in the implants was ABS (Acrylonitrile Butadiene Styrene). Tensile tests are performed on ABS for implant manufacturing. Structured Light 3D Scanner is used to scan a life-size human mandible and the Standard Triangular Language (STL) file was created that file has been used in all the processes involved in the modeling and manufacturing of the Human Mandible by Rapid prototyping on ABS. FEM analysis is done on said material at different orientations using ANSYS 2021. From the test results it is found that the ABS material can sustain more than the required average bite force. Furthermore, a comparison of stress and load-bearing ability of bone and ABS is done to confirm the viability as a replacement material for bone in the mandible, which was found to be positive. The biocompatibility of ABS with the bloodstream and the body is researched and found to be positive. Implantation methods and bone powder coating variants are researched, to be able to fit the implant in the temporomandibular joint with the fastest recovery time.

Rapid Prototyping of 3D Printed, High Aspect Ratio, Low Noise Amplifier for Active Handheld Sensor Devices

In this paper, we report the use of additive manufacturing methods to fabricate a high aspect ratio, low noise amplifier (LNA) for a handheld active sensor device operating at up to 1 GHz. The new form factor LNA incorporates a modification of a square-shaped commercial off-the-shelf (COTS) LNA into a 5:1 aspect ratio device without a loss in RF performance. For rapid prototyping, we employ both subtractive and additive manufacturing technologies, such as milling, extrusion-based syringe printing, and aerosol jet printing techniques to fabricate both small form factor and high aspect ratio devices. The 5:1 aspect ratio LNA demonstrated a 20% smaller form factor, a gain of 25 dB, and an NF less than 3 dB over an operating frequency range up to 1 GHz, comparable to the COTS LNA. Design, simulation, and experimental results are given to highlight the advantages of 3D printed hybrid electronic technology over the conventional PCB fabrication method for rapid prototyping of RF electronic devices.

Rapid prototyping for quantifying belief weights of competing hypotheses about emergent diseases

Emerging diseases can have devastating consequences for wildlife and require a rapid response. A critical first step towards developing appropriate management is identifying the etiology of the disease, which can be difficult to determine, particularly early in emergence. Gathering and synthesizing existing information about potential disease causes, by leveraging expert knowledge or relevant existing studies, provides a principled approach to quickly inform decision-making and management efforts. Additionally, updating the current state of knowledge as more information becomes available over time can reduce scientific uncertainty and lead to substantial improvement in the decision-making process and the application of management actions that incorporate and adapt to newly acquired scientific understanding. Here we present a rapid prototyping method for quantifying belief weights for competing hypotheses about the etiology of disease using a combination of formal expert elicitation and Bayesian hierarchical modeling. We illustrate the application of this approach for investigating the etiology of stony coral tissue loss disease (SCTLD) and discuss the opportunities and challenges of this approach for addressing emergent diseases. Lastly, we detail how our work may apply to other pressing management or conservation problems that require quick responses. We found the rapid prototyping methods to be an efficient and rapid means to narrow down the number of potential hypotheses, synthesize current understanding, and help prioritize future studies and experiments. This approach is rapid by providing a snapshot assessment of the current state of knowledge. It can also be updated periodically (e.g., annually) to assess changes in belief weights over time as scientific understanding increases. Synthesis and applications: The rapid prototyping approaches demonstrated here can be used to combine knowledge from multiple experts and/or studies to help with fast decision-making needed for urgent conservation issues including emerging diseases and other management problems that require rapid responses. These approaches can also be used to adjust belief weights over time as studies and expert knowledge accumulate and can be a helpful tool for adapting management decisions.

High-throughput fabrication of large-scale metasurfaces using electron-beam lithography with SU-8 gratings for multilevel security printing

The field of metasurface research has rapidly developed in the past decade. Electron-beam lithography (EBL) is an excellent tool used for rapid prototyping of metasurfaces. However, Gaussian-beam EBL generally struggles with low throughput. In conjunction with the recent rise of interest in metasurfaces made of low-index dielectric materials, we propose in this study the use of a relatively unexplored chemically amplified resist, SU-8 with EBL, as a method for rapid prototyping of low-index metasurfaces. We demonstrate the use of SU-8 grating on silicon for cost-efficient fabrication of an all-dielectric multilevel security print for anti-counterfeiting purposes, which encrypt different optical information with different light illumination conditions, namely, bright-field reflection, dark-field reflection, and cross-polarized reflection. The large-scale print (1 mm2) could be exposed in a relatively short time (∼11 min) due to the ultrahigh sensitivity of the resist, while the feature size of ∼200 nm was maintained, demonstrating that SU-8 EBL resist serves as a good candidate for rapid prototyping of metasurface designs. Our results could find applications in the general area of increasing EBL patterning speed for a variety of other devices and structures.

Rapid Prototyping of Three-Phase AC Machine Drive System with Subtractive and Additive Manufacturing

We propose a method for rapid prototyping of a three-phase AC drive system for educational purposes. The proposed method allows college students to design and manufacture a drive system comprising three-phase inverters, a permanent-magnet (PM) machine, a controller, and sensors within a semester. The rapid prototyping process, which requires less than a day, enables efficient iteration and testing during the development process. In addition to addressing the electrical design considerations, this study also addresses the mechanical aspects of the drive system, including the use of coreless PM machines fabricated, using additive manufacturing technology, and the inverter manufacturing process, utilizing an auto-milling machine. Finally, we provide details of the rapid prototyping of closed-loop control, based on sensor feedback to regulate the rotating magnetic fields and output torque.

Robustness optimization for rapid prototyping of functional artifacts based on visualized computing digital twins

This study presents a robustness optimization method for rapid prototyping (RP) of functional artifacts based on visualized computing digital twins (VCDT). A generalized multiobjective robustness optimization model for RP of scheme design prototype was first built, where thermal, structural, and multidisciplinary knowledge could be integrated for visualization. To implement visualized computing, the membership function of fuzzy decision-making was optimized using a genetic algorithm. Transient thermodynamic, structural statics, and flow field analyses were conducted, especially for glass fiber composite materials, which have the characteristics of high strength, corrosion resistance, temperature resistance, dimensional stability, and electrical insulation. An electrothermal experiment was performed by measuring the temperature and changes in temperature during RP. Infrared thermographs were obtained using thermal field measurements to determine the temperature distribution. A numerical analysis of a lightweight ribbed ergonomic artifact is presented to illustrate the VCDT. Moreover, manufacturability was verified based on a thermal-solid coupled finite element analysis. The physical experiment and practice proved that the proposed VCDT provided a robust design paradigm for a layered RP between the steady balance of electrothermal regulation and manufacturing efficacy under hybrid uncertainties.