Manufacturing 3D Printing Research Articles

3D printed passive end-effector for industrial collaborative robotic arms

The work focuses on the design and prototyping of a novel end-effector for a collaborative robotic arm allowing to grab and drag industrial packages without lifting them. The proposed solution consists of a passive 3D-printed end-effector manufactured using carbon fibre reinforced Onyx material. Thanks to the entirely passive mechanical actuation that exploits the compliance of the main chassis, this end-effector features a simple, scalable, and inexpensive structure. This lightweight end-effector is specifically designed for small and low payload collaborative robotic arms. Specifically, the proposed end-effector includes three main parts. First, a thin blade, with the main function of separating boxes that are close to each other. Second, a rocker arm - rod mechanism, which allows an opposable bracket to be moved in order to grab the correspondent package. This is proportionally and passively actuated by the contact pressure between the package, during its grip, and a paddle (third part), which is composed of a flat leverage and three flexural springs to counterbalance the pushing force. This paddle and the main body of the gripper were designed as a single part exploiting 3D printing manufacturing capabilities. Moreover, we implemented a Simscape dynamic model that predicts the functionality of the end-effector during standard operations. The work shows how to design, develop and validate a new low cost, passive end-effector mainly oriented to collaborative robots. The final prototype demonstrates its entire functionality, and proves fabricability through 3D printing, thus minimizing production costs, weight, and time.

Correlation between Geometrical Accuracy and Building Angle of 3D Printed Flat Plate with Circular Hole of Aluminum Alloy and Polyamide

Among variety of 3D printing or additive manufacturing methods, the laser power bed fusion (LPBF) technology for metals is now widely spread. In this study, the geometrical accuracy of 3D printed circular hole in a flat plate was investigated using aluminum alloy, Al-Si10-Mg, and polyamide, PA12. Some types of geometrical imperfections have been reported, for instance, in lattice structures or for overhang structures, but the distortion of a circular hole in a component made by LPBF has not yet been discussed in detail. This paper revealed the correlation between the geometrical parameters for distorted circular hole and the building angle. This enabled us to predict the distortion for unexperienced building angle by the interpolation, and to perform finite element analysis of mechanical behavior of a component with a circular hole. The influence of the geometrical inaccuracy on the mechanical behavior and that of the variability in mechanical properties were compared, and the former was found to be more influential. Finally, the geometry compensation in the design phase was also discussed using the statistically measured database.

Dimension synthesis of a 2T2R curved layer FDM 3D printer

3D printing or Additive Manufacturing (AM) is significant in various applications. The authors’ previous research indicates that higher-degree-of-freedom (DOF) 3D printers have the potential for curved layer printing and multi-direction AM. Hence, this paper focuses on designing a novel 2T2R FDM 3D printer. Performance-chart-based design methodology (PCbDM) has been used for multiple parameters optimization problems due to its reliability, globality, and intuition. While its limitation is the number of optimization parameters less than four. The printer’s print head is attached to a planar parallel 1T1R mechanism (4R1P, 3R1P, and passive P). Objectives and requirements require the print head to move over a more considerable distance with a constant swing range and proper pressure angle. So, the 4R1P five-bar (virtual double-rocker, crank-rocker, and rocker-crank) has been investigated to facilitate PCbDM. Meanwhile, one DOF remote center of motion (RCM) mechanism has been integrated for decoupling motion control. Finally, the selected parameters are verified by comparing the numerical and simulation results and experiments. Besides, this novel 3D printer’s initial feasibility of flat and curved layer printing is studied with several printed parts to give qualitative analyses. This early-stage work generally intends to investigate the dimension synthesis and show the resulting 2T2R-type rotary 3D printer’s initial feasibility for curved printing. The research can help people understand how to carry out the dimension synthesis of 4R1P and a novel mechanism with multi-chain with the help of Grashof criteria to reduce the design space dimensionality.

Emerging Digital Technologies in the Workplace. 3D Printing, Work Organization and Job Quality at the Airbus Spain Case Study

This paper approaches a case study of Airbus Spain in the context of the studies on digital transformation in the workplace, with the aim of examining how the company manages the impact of digital transformation in the workplace and its impact on work organization and job quality. Airbus has based its technological change in 3D printing and additive layer manufacturing (ALM), with deep implications in its work processes, training and required skills. The experience of the social actors involved in these processes is analyzed by applying qualitative methods (key informant’s interviews). The results point to an increase in the autonomy and responsibility of the employees due to the implementation of new digital technologies that have brought about a change in organizational culture. Positive effects on job quality are also found through the reduction of work risks, improvement of the physical and social environment, reduction of the intensity of physical work and improvement of employees’ career prospects.

A study on the prospects of vacuum gamma irradiation to enhance crosslinking for 3D-Printing PLA/MCC biocomposite filaments

3D-printing or Additive Manufacturing (AM) has been growing as a rapid manufacturing process for many different applications, with Poly (Lactic Acid) as one of the most used materials for 3D-printing. PLA shows great promise for many applications to achieve the goals of the SDGs due to its biodegradability and biocompatibility but lacks when it comes to mechanical strength and thermal resistance. In this study, microcrystalline cellulose (MCC) fibers were introduced as a reinforcement to PLA. The biocomposite filaments were irradiated in a vacuum to enhance the crosslinking. Gamma-ray irradiation in a vacuum has successfully shown signs of crosslinking by increasing the tensile strength and thermal stability of the biocomposite, indicating an enhancement for PLA/MCC for various applications. On the other hand, changes in thermal properties also indicated that irradiation may reduce the processability of the composite, so it is necessary to study the conditions under which the mechanical properties and processability are compatible.

3D printing technologies and photopolymer resins used in fixed prosthetic rehabilitation

The utilization of computer-aided design and production has become increasingly prevalent in the dental industry, as in many other fields. Additive manufacturing, a computer-aided production method, has brought about numerous advantages such as fast and precise production, design freedom, and cost and time savings. It is anticipated that 3D printers will become the primary method for digital processing in dentistry in the future. The objective of this article is to offer a comprehensive introduction to the present-day manufacturing methods for fixed prosthetic rehabilitation, focusing on the 3D printing manufacturing and photopolymer resin materials employed in these technologies.

3D printed lattice metal structures for enhanced heat transfer in latent heat storage systems

The low thermal conductivity of Phase Change Materials (PCMs), e.g., paraffin waxes, is one of the main drawbacks of latent heat storage, especially when fast charging and discharging cycles are required. The introduction of highly conductive fillers in the PCM matrix may be an effective solution; however, it is difficult to grant their stable and homogeneous dispersion, which therefore limits the resulting enhancement of the overall thermal conductivity. Metal 3D printing or additive manufacturing, instead, allows to manufacture complex geometries with precise patterns, therefore allowing the design of optimal paths for heat conduction within the PCM. In this work, a device-scale latent heat storage system operating at medium temperatures (∼90 ℃) was manufactured and characterized. Its innovative design relies on a 3D Cartesian metal lattice, fabricated via laser powder bed fusion, to achieve higher specific power densities. Numerical and experimental tests demonstrated remarkable specific power (approximately 714 ± 17 W kg−1 and 1310 ± 48 W kg−1 during heat charge and discharge, respectively). Moreover, the device performance remained stable over multiple charging and discharging cycles. Finally, simulation results were used to infer general design guidelines to further enhance the device performance. This work aims at promoting the use of metal additive manufacturing to design efficient and responsive thermal energy storage units for medium-sized applications, such as in the automotive sector (e.g. speed up of the engine warm up or as an auxiliary for other enhanced thermal management strategies).

Facile Handling of 3D Two‐Photon Polymerized Microstructures by Ultra‐Conformable Freestanding Polymeric Membranes

AbstractMicro‐nano‐fabrication on objects with complex surfaces is essential for the development of technologies in the growing fields of flexible electronics and photonics. Various strategies are devised to extend the fabrication from conventional planar substrates to curved ones, however, significant challenges still exist, especially in the framework of 3D printing and additive manufacturing. In this study, a novel technique is presented to realize 3D micro‐structures on arbitrary complex surfaces providing an extreme level of conformability. This method relies on the fabrication of micro‐structures via two‐photon polymerization on polymeric nano‐membranes that can be efficiently transferred to a specific target. Ultra‐thin polymeric films are exploited as the support to suspend and transfer the printed micro‐structures on the predefined surface. The nanofilm can finally be easily removed, apart from the region underneath the printed elements where it serves as a few tens of nanometers adhesive. The repeatability and feasibility of the proposed process are investigated and shown to provide large flexibility of choice on the printed structures, materials used, transfer procedures, and targeted substrate geometries. By integration with standard fabrication processes, the described technique offers a great potential for the development of next‐generation multidimensional/multi‐material micro‐nano‐technologies.

Emerging 3D printed thermal insulating materials for sustainable approach: A review and a way forward

AbstractThermal insulating materials are such materials that do not allow the movement of heat through themselves. The material must have lower thermal conductivity to work efficiently as an insulator. Conventionally glass wool, calcium silicates, concrete, and processed wood particle boards are well‐known thermal insulators used for construction purposes. The thermal conductivity of glass wool is near about ~0.02–0.04 W/mK, and calcium silicates are also around ~0.08 W/mK. In contrast to these fabrication techniques, 3D printing or additive manufacturing has emerged as the most in‐demand fabrication method. The scope of versatility in shapes, design, dimension, and finish that 3D printing yields are enormous, and their performance is significantly comparable and, in some cases, better than conventionally prepared materials. 3D printing includes various methods such as FDM, SLA, SLS, DIW, and so on. Recent literature has shown the fabrication of thermally insulating material using raw materials like silk fiber, fly ash, cement, polymer composite, metal oxides, and so on, through additive manufacturing. These materials have very low thermal conductivity, as low as 0.03–0.08 W/mK for SLA and DIW printed silivoxel, cellulose nanocrystals composites having 0.08–0.09 W/mK and 0.04 for PU and cork composites. The low thermal conductivity values indicate their possible and efficient application as thermal insulators.

Optimasi Parameter Produk 3D Printing Terhadap Kekuatan Bending Dengan Menggunakan Filamen Nylon

3D Printing or additive manufacturing is a new technology for the industry. The machine has created an object for 3D layer by layer that makes a product with accurate dimensions and certain patterns, as the technology developed, the manufacturing industry began to develop products using additive material methods known as rapid prototyping or layer manufacturing, one of which was the use of 3D printer technology. This research was conducted on a 3D Printing FDM model Ender 3 Pro with dimensions 220 mm x 220 mm x 250 mm and using a nozzle with a 0,4 mm diameter. The material for this research is Nylon 6 with a diameter of 1,75 mm with variations in Layer Thickness (0,21 mm 0,24mm 0,27 mm), Infill Pattern (Rectilinear, Grid, Wiggle), Z-Orientation (0°,15°,30°) which will be determined in Ultimaker Cura 4.4.0 software and Taguchi Method in software minitab19.1. resulting in OA L9 with 3 times replication printed sample. The results obtained after testing the highest bending stress values are found in the 9th specimen which is 16,7 MPa average with 0,27 Layer Thickness, Wiggle Infill Pattern, and 15° Z-Orientation. While the lowest bending stress values are found in the 4th specimen which is 12,7 MPa average with 0,24mm Layer Thickness, Rectilinear Infill Pattern, and 15° Z-Orientation.

Application of 3D printing concepts in the Architecture Engineering and Construction (AEC) industry - A scientometric review

The construction industry builds the essential infrastructure and contributes to the economic development of any nation. The productivity of the construction industry has been lagging behind manufacturing for many decades. The COVID-19 pandemic has exposed the vulnerability of the industry and its severe dependencies on manual, labour-oriented practices. The industry needs to become resilient and rebound quickly to recover from the impacts of the pandemic. The 3D printing or additive manufacturing concept offers to automate the processes of construction, improve efficiencies in design & construction, reduce wastage and sustainable development. The present paper intends to summarize the developments, trends, and application areas through a scientometric review. Research articles were obtained from the Scopus database. The USA leads the research studies followed by China, Australia, the UK and Germany. 339 documents were obtained from the initial search. These were systematically filtered for review through the PRISMA framework. The screened 193 articles were quantitatively analyzed through the VOS viewer software. The study summarizes the current research trends, themes, and future research trends. The study contributes to the existing body of knowledge and intends to raise awareness of the concept and encourage researchers and practitioners to adopt the concept on a larger scale, especially in India.

Experimental and Numerical Studies on the Hilbert Fractal Architecture as an Acoustic Metamaterial

Experiments and numerical methods were used to investigate the key parameters which affect the transmission loss behaviour of Hilbert fractal acoustic metamaterials. The tests were conducted using a four-microphone impedance tube, and the numerical simulation was performed using COMSOL Multiphysics software. Fractal order and cavity slot widths on Hilbert fractal metamaterials were investigated. 3D printing manufacturing techniques were used to make polylactic acid specimens. The COMSOL model developed utilised thermo-viscous and lossless domains with boundary layer mesh in the fractal cavities. The tests and simulations' frequency range were 0.2 kHz to 3.0 kHz, with parametric gap widths ranging from 0.5 mm to 3.0 mm. There is a reasonable agreement between the numerical models and the experimental results; the second-order Hilbert fractal had the most significant effect on transmission loss, with an experimental peak of nearly 50 dB around 1600 Hz. Moreover, multiple transmission loss peaks were observed as a function of the gap width in the five Hilbert fractal orders studied. The gap width is one of the critical parameters for optimising the performance of the Hilbert fractal as an acoustic metamaterial.

FDM-based additive manufacturing of recycled thermoplastics and associated composites.

Hailed since the fourth industrial revolution, three-dimensional (3D) printing or additive manufacturing (AM) has been extensively implemented in various manufacturing sectors. This process is popular for generating regular products and incorporating innovative designs into the components like auxetic structures, such as fabrication of engineering products, customized implants and sophisticated biomedical devices. Over the years, one of the interesting outputs of this emerging technology is the reuse of waste thermoplastic materials to produce competent products through the fused deposition modeling (FDM) technique. The strength of FDM components produced from thermoplastic waste is lower than that of virgin plastic FDM counterparts. So, there is a need to understand the significant changes in the recycled thermoplastic material during subsequent extrusions, which are chain scission, change in viscosity and breaking strength. The use of additives has been a promising solution to improve the performance of recycled material for 3D printing applications. Hence, this study aims to provide an overview of reusing plastic waste through FDM-based 3D printing. This review summarizes the current knowledge about the effect of processing on thermo-mechanical properties of recycled plastic FDM parts and the use of various additives to improve the overall quality. In addition, two case studies from open literature have been demonstrated to explain the use of FDM and associated technology for plastic recycling.

3D printing of pharmaceuticals for disease treatment.

Three-dimensional (3D) printing or Additive manufacturing has paved the way for developing and manufacturing pharmaceuticals in a personalized manner for patients with high volume and rare diseases. The traditional pharmaceutical manufacturing process involves the utilization of various excipients to facilitate the stages of blending, mixing, pressing, releasing, and packaging. In some cases, these excipients cause serious side effects to the patients. The 3D printing of pharmaceutical manufacturing avoids the need for excessive excipients. The two major components of a 3D printed tablet or dosage form are polymer matrix and drug component alone. Hence the usage of the 3D printed dosage forms for disease treatment will avoid unwanted side effects and provide higher therapeutic efficacy. With respect to the benefits of the 3D printed pharmaceuticals, the present review was constructed by discussing the role of 3D printing in producing formulations of various dosage forms such as fast and slow releasing, buccal delivery, and localized delivery. The dosage forms are polymeric tablets, nanoparticles, scaffolds, and films employed for treating different diseases.

Future of Orthodontics-A Systematic Review and Meta-Analysis on the Emerging Trends in This Field.

Technology is rapidly evolving in the modern world, and the accompanying developments due to its influence are shaping each and every aspect of our life, with the field of orthodontics being no exception. This systematic review and meta-analysis aimed to examine such trends in orthodontics and hypothesize which ones would emerge and continue in the near future. After a thorough search of online journals using keywords such as "3D printing," "Aligners," "Artificial intelligence," "Future trends," "Orthodontics," and "Teleorthodontics" across databases of PubMed-MEDLINE, Web of Science, Cochrane, and Scopus, a total of 634 papers were initially recovered. Technological advancements in 3D printing, Computer-aided design and Computer-aided manufacturing (CAD/CAM), biopolymers and Teleorthodontics were the most important categories of development seen across the 17 studies that we selected for our review. All the investigations selected for this systematic review depicted aspects of orthodontics that were influenced by rapid technological changes and could potentially become mainstream in the coming times. However, caution was sought to be observed in the usage/adoption of some of these trends, with social media usage amongst both patients as well as orthodontists being a prime example of this.

Additive manufacturing technologies with emphasis on stereolithography 3D printing in pharmaceutical and medical applications: A review

Three-dimensional (3D) printing or Additive Manufacturing (AM) technology is an innovative tool with great potential and diverse applications in various fields. As 3D printing has been burgeoning in recent times, a tremendous transformation can be envisaged in medical care, especially the manufacturing procedures leading to personalized medicine. Stereolithography (SLA), a vat-photopolymerization technique, that uses a laser beam, is known for its ability to fabricate complex 3D structures ranging from micron-size needles to life-size organs, because of its high resolution, precision, accuracy, and speed. This review presents a glimpse of varied 3D printing techniques, mainly expounding SLA in terms of the materials used, the orientation of printing, and the working mechanisms. The previous works that focused on developing pharmaceutical dosage forms, drug-eluting devices, and tissue scaffolds are presented in this paper, followed by the challenges associated with SLA from an industrial and regulatory perspective. Due to its excellent advantages, this technology could transform the conventional “one dose fits all” concept to bring digitalized patient-centric medication into reality.

3D Printing in a hospital: Centralized clinical implementation and applications for comprehensive care.

This educational article discusses the use of 3D printing or additive manufacturing in hospitals, not just for rapid prototyping but also for creating end-use products, such as clinical, diagnostic, and educational tools. The flexibility of 3D printing is valuable for creating patient-specific medical devices, custom surgical tools, anatomical models, implants, research tools and on-demand parts, among others. The advantages of and requirements for implementing a clinical 3D printing service in a hospital environment are discussed, including centralized 3D printing management, technology, example use cases, and considerations for implementation. The article provides an overview for other institutions to reference in setting up or organizing their clinical 3D printing services and is applicable to general hospitals or various sub-specialty practices.

The 3D-Printed Non-Radiating Edge Gap-Coupled Curved Patch Antenna

The use of parasitic resonant patches is a widespread technique to improve the bandwidth of microstrip patch antennas. Exploiting the free form-factor allowed by 3D-printing manufacturing technology, we present here a novel curved patch antenna layout, based on the non-radiating edge gap-coupled patch configuration. The proposed antenna is composed of a central curved patch, fed by a coaxial probe, and two gap-coupled parasitic side curved patches. This solution features a percentage impedance bandwidth of 16.3% using symmetrical parasitic side patches and 31.5% using asymmetrical side patches. A significant improvement of the bandwidth in comparison with both the standard non-radiating edge gap-coupled microstrip antenna (6.1% bandwidth) and the standard curved patch antenna (9% bandwidth) is achieved. Design and optimization of the proposed configuration are performed using the commercial software CST Studio Suite at the center frequency of 2.45 GHz. Prototypes of the symmetrical curved non-radiating edge gap-coupled patch antenna have been manufactured for the experimental verification, using a curved 3Dprinted polylactic acid (PLA) substrate, fabricated with the commercial 3D printer PRUSA MK3S+, and a 50μm-thick adhesive aluminum tape for the metallization. Measured results show a very good agreement with simulations.

A Review: 3D Printing

Abstract: 3D printing or additive manufacturing is a method of creating three dimensional solid matters from a digital file. The design of a 3D printed object is accomplish using additive processes it is also called as RAPID PROTOTYPING. In an additive process an object is manufactured by dozing consecution layers of material as far as the entire object is created.3D concept has the capabilities to furnish benefits for patients, pharmacists and the pharmaceutical industry alike by empower the on-demand design and production of various formulations with individualized dosages, shapes, sizes, drug release and multi-drug combinations. This article criticizing the major benefits for using 3D printing in pharmaceuticals, highlighting the crucial role that healthcare staff play, and will continue to play, in the future implementation of 3D printing into the pharmaceutical sector.

Convertible Thermal Meta-Structures via Hybrid Manufacturing of Stereolithography Apparatus 3D Printing and Surface Metallization for Thermal Flow Manipulation

For manipulating heat flow according to human desire, thermal metamaterial structures (meta-structures) have attracted growing interest. Based on the transformation thermotics and the effective medium approximation theory, we designed and fabricated a convertible thermal meta-structural device to demonstrate that multiple different heat-flow manipulations could be conducted using a single thermal meta-structural device. The convertible meta-structures were designed by discretizing a two-dimensional plane and separating multiple square unit modules with stripe-shaped dissimilar materials of the Polydimethylsiloxane (PDMS) and solid resin with surface metallized copper (Cu). The convertible thermal meta-structure device with a relatively high geometric accuracy was fabricated via a proposed hybrid manufacturing path of "Stereolithography Apparatus (SLA) 3D printing-electroless plating-electroplating-thermally insulated packaging". The thermal manipulation features were numerically simulated and preliminarily verified by experimental testing. Using multiple dispersed square unit modules to replace an annular region of the thermal meta-structure exhibited different thermal flow functions, including thermal cloak, thermal concentration, thermal rotation, and thermal dispersion, through the unique geometric design of the heat-flow transfer direction within each module. By rotating each square unit module at a specific angle and arranging the modules, similar to a "jigsaw puzzle", the convertibility among different thermal manipulation functions was achieved. This path is anticipated to provide a new strategy for multifunctional meta-structures in thermo-physics and its potential engineering applications.