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In this study, a program called additive manufacturing guide (AM Guide) based on Excel VBA was constructed with a database that contains 401 different materials from 46 main material groups used in AM processes. This program could suggest material selection advice for 14 different material selection criteria for the part to be designed. In addition, the program could suggest seven frequently preferred design parameters or boundary conditions in terms of manufacturability for 21 basic materials in four main material groups. As a result of the study, the developed program (AM Guide) was tested with four case studies from the extant literature and presented the advantage of the material selection for the AM environments. For AM technology to be used effectively and become widespread, it is necessary to have foresight and perspective in terms of material choices. In this context, there is a need for a guide to users on issues such as material selection of the parts to be produced with AM technologies. Three benchmark examples were conducted in this paper. For the first example, the developed AM guide offered 91 different alternative materials against the six alternatives for the same problem from the extant literature. Also, the developed AM guide proposed 134 and 122 different materials for cases 2 and 3, respectively, against 5 and 6 alternatives offered from the extant literature for the same cases.

This paper presents preliminary results of a high speed 1550 nm indium gallium arsenide (InGaAs)-based mesa-type modified uni-traveling carrier photodiode (M-UTC-PD) structure. Conventional UTC-PD refers to P-I-N type photodiodes which selectively use electrons as active carriers. Photons absorbed in the relatively thin P-type absorber create minority carriers which are field accelerated toward a depleted collector thereby establishing high velocity ballistic transport, making these structures applicable for high speed applications. The M-UTC-PD structure presented uses spatially tailored P-type absorber regions to limit minority carrier generation both in the lateral and axial dimensions. Utilizing an otherwise conventional UTC-PD epitaxial structure where the top P-type layers are undoped, the spatially tailored P-type regions are defined by closed ampoule Zinc diffusion techniques. The M-UTC-PD structure presented utilizes a series of nested p-doped rings within a mesa structure to limit dark current and reduce overall capacitance to improve high speed operation. Two photodiode structures will be investigated for this research project, a conventional UTC-PD structure and a modified structure, utilizing similar device designs, epitaxial designs and fabrication processes. The conventional structure will be utilized for fabrication process development, verification of epi quality and development of rapid prototyping approach toward chip-based testing and subsequent high speed RF testing procedures. Conventional UTC-PD device results will be used as a comparison to quantify the performance of the M-UTC-PD structure utilizing Zn-doped defined p-type absorber regions. Results are given for chip tests of UTC-PD chips verifying epitaxial quality and fabrication process, subsequent testing of packaged devices and RF analysis remains. Process development of the Zn-doped devices is underway, once completed, these devices will be compared to the base design to quantify performance enhancement associated with the modified design.

This study discusses a head injury mechanism in case of a human head subjected to impact, from results of impact experiments by using a physical model of a human head with high-shape fidelity. The physical model was constructed by using rapid prototyping technology from the three-dimensional CAD data, which obtained from CT/MRI images of a subject's head. As results of the experiments, positive pressure responses occurred at the impacted site, whereas negative pressure responses occurred at opposite the impacted site. Moreover, the absolute maximum value of pressure occurring at the frontal region of the intracranial space of the head model resulted in same or higher than that at the occipital site in each case that the impact force was imposed on frontal or occipital region. This result has not been showed in other study using simple shape physical models. And, the result corresponds with clinical evidences that brain contusion mainly occurs at the frontal part in each impact direction. Thus, physical model with accurate skull shape is needed to clarify the mechanism of brain contusion.

Rapid prototyping (RP) technologies have been extensively applied to build products in recent decades. The area-forming rapid prototyping is an emerging RP technology with the advantages of a simple procedure with a short processing time. With the expansion in fields of application, the strictness on product quality has also increased. The dimensional accuracy of a product is one of the most critical quality characteristics. In order to improve the dimensional accuracy of a product from an area-forming RP system, this study optimizes the seven factors via the Taguchi method, and the result is verified with an extra sample.

Digital scan conversion (DSC) is the process of converting received ultrasound signals, or echoes, in multi-scan lines, at varying angles (polar coordinate), to a Cartesian raster format for displaying. In this paper, we propose a new DSC technique that uses nearest-neighbor interpolation and the linear interpolation between adjacent scan lines to reduce artifacts on the far field, with smaller angular separation between the interpolated lines. A hardware implementation is described that uses only a FIFO register and a display memory. Rapid prototyping using an ARM processor with FPGA resources is achieved to validate the operation of the described system. Experimental results of the implemented design demonstrated the expected operation of the reduced complexity architecture in term of needed memory. Also, the performance of retrieved images were increased.

Current multimedia design processes suffer from the excessively large time spent on testing new IP-blocks with references based on large video encoders specifications (usually several thousands lines of code). The appropriate testing of a single IP-block may require the conversion of the overall encoder from software to hardware, which is difficult to complete in the short time required by the competition-driven reduced time-to-market demanded for the adoption of a new video coding standard. This paper presents a new design flow to accelerate the conformance testing of an IP-block using the H.264/AVC software reference model. An example block of the simplified 8 × 8 transformation and quantization, which is adopted in FRExt, is provided as a case study demonstrating the effectiveness of the approach.

Multimedia systems incorporating hyperlinks and user interaction can be prototyped using TAOML, an extension of HTML. TAOML is used to define a Teleaction Object (TAO) which is a multimedia object with associated hypergraph structure and knowledge structure The hypergraph structure supports the effective presentation and efficient communication of multimedia information. In this paper, a formal specification methodology for TAOs using Symbol Relation (SR) grammars is described. An attributed SR grammar is then introduced in order to associate knowledge with the TAO. The limitations to achieve an efficient parser are given. The grammatical formalism allows for validation and verification of the system specification. This methodology provides a principled approach to specify, verify, validate and prototype multimedia applications.

We describe IC card, which is a visual specification scheme for the rapid prototyping of time-critical applications. The software developer can use IC cards to describe the entities of an application and their interaction patterns to capture user's requirements. The IC card management system, which is a visual specification tool, supports the creation and editing of IC cards and the transformation of IC cards into an XML specification. The XML specification can be transformed into an IC system and compiled into codes, thus creating a working prototype. Application examples are described.

The purpose of this study was to investigate the attachment and proliferation of cells on selective laser-sintered (SLS) polycaprolactone (PCL) scaffolds coated with gelatin for cartilage tissue engineering using chondrocytes isolated from the articular cartilage of swine. Scaffolds without modification were used as control groups. Cell proliferation was measured by cell count 1, 3 and 5 days after cell seeding into the scaffolds. The biocompatibility of the scaffold was examined by scanning electron microscopy (SEM). The PCL scaffolds coated with gelatin had higher hydrophilicity. The results provided a useful strategy for modifying the microenvironments to increase cell attachment, growth and the formation of extracellular matrix on scaffolds for cartilage tissue engineering.

Advanced three-dimensional (3D) models have played more and more essential roles in orthopedics surgical interventions. In order to improve the clinical outcomes of knee surgery (KS) including minimally invasive knee surgery (MIKS), the melted extrusion modeling (MEM), a rapid prototyping (RP) technique, was used efficiently to fabricate real life-size 3D physical models of interesting knees. The applications and advantages of the tangible RP-constructed 3D models in KS were elucidated in this study. As a result, better preparation including optimal preoperative planning was made so that KS could be performed in an accurate, safe and fast manner for each case. Besides, the surgical skills of MIKS were substantially improved. Therefore, the results suggest that KS can benefit much from the advanced 3D modeling technique.

Owing to stiff competition globally, the business operation of traditional industries, like the mould and die industry in Taiwan, urgently needs to be modernized. A wide spectrum of IT-tools and a variety of different computer-aided systems are currently available to provide best-in-class solutions for executing manufacturing and marketing tasks. Our aim in this project is to integrate the technologies of reverse engineering (RE), rapid prototyping (RP), rapid tooling (RT) and virtual reality (VR) for mould and die industries to effectively improve the performance of creative design, rapid manufacturing, training and marketing. The integration of RE/RP/RT technologies is known as 3R technology. From the reports, 3R technologies are capable of improving conceptual design quickly and effectively. With the improvement of computer and Internet technologies, the interaction of webbed VR has recently become an important business means to promote creative training and marketing. We call the integration of 3R and VR techniques 4R technology. This present methodology can help enterprises improve their capability for global competition.

This paper presents a novel integrated system of rapid product development for reducing the time and cost of product development. The system is composed of four building blocks — digital prototype, virtual prototype, physical prototype and rapid tooling manufacturing system. It can aid effectively in product design, analysis, prototype, mould, and manufacturing process development by integrating closely the various advanced manufacturing technologies which involve the 3D CAD, CAE, reverse engineering, rapid prototyping and rapid tooling. Furthermore, two actual examples are provided to illustrate the application of this integrated system. The results indicate that the system has a high potential to reduce further the cycle and cost of product development.

Rapid Prototyping (RP) technology has become the powerful tool for product development in almost every branch of engineering. Many new and upcoming processes offer means for the fast creation of models with steadily increasing accuracy, built speed, other model properties and economic advantages. Fused Deposition Modeling (FDM) is the most famous and commercially available RP system. This paper presents the application of Utility concept with Taguchi method for multiresponse optimization of the FDM process. Stratatys Fortus 400mc FDM setup is used to conduct experiments as per Taguchi’s L₉ orthogonal array. FDM parameters: Layer thickness, part orientation and raster angle were optimized based on multiple responses, i.e. tensile, flexural, impact and compressive strength. The optimum process parameters are calculated using utility concept. The Analysis of variance (ANOVA) is applied to find out the most significant factor. It has been found that layer thickness is the most significant factor, followed by part orientation and raster angle. The confirmation tests with optimal levels of process parameters are conducted to illustrate the efficacy of the proposed method. It is found that optimum combination of process parameters gives the highest utility value, which indicates that multiresponses of the FDM process can be improved through this approach.

Selective laser sintering (SLS) is an additive manufacturing technology whereby parts are built through selective consolidation of a powder by a laser beam. Recently, Polypropylene (PP) has been used in the SLS because of its appropriate mechanical performance as well as low cost and density. In the SLS, laser parameters are very effective on the mechanical properties of the sintered parts. In this study, the effects of the laser parameters including power, the laser scanning speed, and the laser scanning pattern on the tensile strength of the sintered samples were experimentally investigated. The PP and PP/CNT (carbon nanotube) composites were used as raw materials and the results were compared. Taguchi method was employed as the experimental design, and optimal levels of parameters were extracted using signal-to-noise analysis. The main effects of factors and interactions were considered in this paper. The results show that the laser scanning pattern and the laser power have the most effects on the tensile strength of the produced samples. In addition, the comparison between the results of the experiments demonstrates an increase in the tensile strength, which is 15% in maximum value, by adding CNT to PP.

Main advances in artificial intelligence robotics are algorithms, embodied in software on the level of application software. Low-level hardware programming, electronic, and mechanics are the necessary basis to enable the implementation of newly developed algorithms. Complex autonomous systems are challenged by the tasks that require fast reactions, resulting in high accelerations and forces. These systems, therefore, generally need low masses, stiff limbs, and a precise control.

To boost AI-research, more robotic systems that are appropriate to specific research questions are needed. Mechanical design is, therefore, faced with the task to provide specialized systems with a given amount of time and factors of production. This paper outlines an approach to increase the efficiency of engineering design in the field of robotics by analyzing the bilateral influence of the system concept with embodiment design driven by the state of the art small-batch manufacturing technologies.

The humanoid robotic system AILA is presented and the selected steps out of its design process are discussed. A way to clearly state the axioms and requirements that the developed system is based on is presented. The resulting dependencies lead to the embodiment design of the systems components, which are also influenced by the choice of suitable manufacturing technologies.

Health systems were severely strained at the start of the COVID-19 pandemic, where the demand for personal protection equipment (PPE) could not be met. The challenge faced by many countries was how to innovate quickly to create PPE and other needed solutions. The subsequent research gap identified was a lack of practical insights on how to support such novel technology adoption, particularly those that stem from Industry 4.0 (I4.0) within a developing world context. To address this previous literature on I4.0 technology, the role of innovation environments and theoretical principles of technology adoption was reviewed. A practical case from an academic makerspace based in a South African university was then assessed. It was selected due to its direct role in rapid solutions development of PPE using additive manufacturing (AM) until such a time that manufacturers could set up production on a larger scale. It was found that AM and other novel technologies have facilitated innovative solutions to address the significant impacts of the pandemic. Key to which were practices identified of an innovation environment that supported early-stage adoption of AM to achieve this even in a developing country context. The findings imply that innovation environments offer an agile platform to leverage innovation by streamlining certain critical success factors of I4.0 technology adoption, which is presented in a model. However, individual skills developed by such environments to enhance innovation capabilities within this paradigm require further research.

Diffractive Optical Elements (DOE) are often associated with the use of laser beam shaping equipment. They can be controlled and verified flexibly according to application. This paper demonstrates experimentally the lithography technique used to fabricate a DOE with precisely aligned pattern on a polymer surface. We have designed and fabricated a grating on the lens surface using the direct lithography by an Atomic Force Microscope. A description of the optical design is presented along with a discussion on the integrated manipulation system. The fabrication process has been proven to be cost efficient and reliable. It is believed that this technique can also transfer onto a complicated DOE.

Formal control design techniques usually rely on the plant model of a desired system. The plant model can be derived from the foundation principles of the system but often includes unidentified parameters. In order to approximate these unknown parameters, experiments are conducted to collect information from the behavior of plant dynamics. Thus, closed-loop feedback control methods can be formulated upon the estimation of an appropriate plant model using simulation techniques. Rapid prototyping techniques support this design paradigm which requires that the rapid prototype operate in real time, interact with real hardware and have supporting control functionality. This paper delivers a study on the modeling and testing of a gait generation method using a rapid prototyping technique. The objective is to develop a method of rapid prototyping to test new walking algorithms on a real-time robotic system. The paper addresses the drawbacks of a non-real-time simulation by evaluating the locomotion of a six-legged robot in terms of tracking errors and signifies the proposed methodology of tuning the gait generation algorithm online through real-time hardware in loop simulation setup. Finally, the paper inspects the improved locomotion of the robot using the proposed methodology and signifies it as a valid prototyping technique for approximating novel gait generation algorithms on real-time robotic systems.

Micromilling has great potential in producing microdevices for lab-on-a-chip and organ-on-a-chip applications, but has remained under-utilized due to the high machinery costs and limited accessibility. In this paper, we assessed the machining capabilities of a low-cost 3-D mill in polycarbonate material, which were showcased by the production of microfluidic devices. The study demonstrates that this particular mill is well suited for the fabrication of multi-scale microdevices with feature sizes from micrometers to centimeters.

Background: Three-dimensional (3D) printing technology is increasingly commercially viable for pre-surgical planning, intraoperative templating, jig creation and customised implant manufacture. The challenging nature of scaphoid fracture and nonunion surgery make it an obvious target. The aim of this review is to determine the use of 3D printed technologies in the treatment of scaphoid fractures.

Methods: This is a review of the Medline, Embase and Cochrane Library databases examining studies aimed at therapeutic use of 3D printing, also known as rapid prototyping or additive technology, in the treatment of scaphoid fractures. All studies published up to and including November 2020 were included in the search. Relevant data extracted included modality of use (as template/model/guide/prosthesis), operative time, accuracy of reduction, radiation exposure, follow-up duration, time to union, complications and study quality.

Results: A total of 649 articles were identified, of which 12 met the full inclusion criteria. Analysis of the articles showed that 3D printing techniques can be utilised in myriad ways to aid planning and delivery of scaphoid surgery. Percutaneous guides for Kirschner-wire (K-wire) fixation of non-displaced fractures can be created; custom guides can be printed to aid reduction of displaced or non-united fractures; patient-specific total prostheses may recreate near-normal carpal biomechanics and a simple model may help graft harvesting and positioning.

Conclusions: This review found that the use of 3D printed patient-specific models and templates in scaphoid surgery can improve accuracy and speed, and reduce radiation exposure. 3D printed prostheses may also restore near-normal carpal biomechanics without burning bridges for potential future procedures.

Level of Evidence: Level III (Therapeutic)