Rapid Prototyping Applications Research Articles

Indirect fabrication of gelatin scaffolds using rapid prototyping technology

Scaffold-based tissue engineering strategies often face the problem of tissues forming only within the periphery layers of the scaffold due to mass transfer issues. In the present study, we attempt to overcome this limitation by incorporating a three-dimensional (3D) interconnected network of channels within the scaffold as part of the fabrication process so as to enhance nutrient delivery and cell migration. A scaffold material with the ability to foam was also used in conjunction with this process in order to produce highly interconnected pores within the scaffold. This article describes the developmental process of an indirect fabrication approach which involves the application of rapid prototyping (RP) technology as well as the use of a foaming scaffold material to produce highly and uniformly porous scaffolds with complex channel architectures. Finally, cytotoxicity assessment confirmed that the multiple steps involved in the fabrication process did not induce toxicity within the scaffold.

Individual Design and Rapid Prototyping in Reconstruction of Orbital Wall Defects

We examined the application of individual digital design and rapid prototyping in the reconstruction of orbital wall defects for different stages of orbital volume (OV) changes. Patients with unilateral post-traumatic orbital defects underwent individual digital design and rapid prototyping to manufacture specific titanium mesh implants to create ideal OV recovery. Features of orbital wall fracture deformities and OV changes were analyzed and measured with 3-Dimensional Medical Surface Rendering image software system. Most cases involving enophthalmos and diplopia were rectified, except for 5 cases of enophthalmos and 2 cases of diplopia with fresh fractures and 11 cases of enophthalmos and 7 cases of diplopia cases with old fractures. Ocular movements and facial malformations were improved. The OV values between the uninjured and injured sides had a significant deviation (P < .05). The degree of enophthalmos had no significant deviation with OV changes pre- and postoperatively in the early fracture stages. The degree of enophthalmos in the old fracture stages had a significant deviation with OV changes pre- and postoperatively. This study showed that orbital wall fractures can be diagnosed in early fracture stages and that the degree of long-term enophthalmos can be predicted with 3-Dimensional Medical Surface Rendering software. Our results suggest that early-stage orbital wall fractures should recover OV as early as possible, and that advanced stage orbital wall fractures should overcorrect OV. The degree of accuracy and rational of OV reconstruction can be improved by appropriate individual digitalization design and rapid prototyping technology.

歯科医療における Rapid Prototyping（RP）技術の応用

歯科医療における Rapid Prototyping（RP）技術の応用

Part of the Solution

This article presents numerous examples of rapid prototyping applications in the United States and explains its benefits. Constructing housing via rapid prototyping methods is expected to save time and money and bring affordable and environmentally friendly housing to people in need. Using an additive-manufacturing technique for constructing new buildings could provide emergency housing for victims of disasters. The technique could also be used for affordable housing for those in the United States or in third-world countries, or for creating new housing styles that bring curved, organic designs rather than straight surfaces to the homes. In industrialized countries, automating the manufacturing of products such as shoes or cars can cut costs about 25% as compared to manual construction methods. Makers of rapid prototyping technology are using CT scans to create exact-fit implants for craniofacial and maxillofacial operations. The rapid prototyping process is also being matched with humanitarian efforts in another project, this one situated in war-torn Iraq. Analysts suggest that custom medical devices and low-cost housing—affordable for everyone and quick to manufacture accurately—will help grow rapid prototyping into a robust industry.

Low-cost resin infusion mould tooling for carbon fibre composites manufacture

This article describes the research to date carried out under the BAE Systems/Engineering and Physical Sciences Research Council (EPSRC)-funded programme ‘Flapless Aerial Vehicle Integrated Interdisciplinary Research’ (FLAVIIR), aimed at developing innovative technologies for the low-cost manufacture of next-generation Unmanned Aerial Vehicles. The aim of the researchers in FLAVIIR was to develop low-cost innovative tooling technologies to enable the affordable manufacture of complex composite aerospace structures. The advances in tooling technology were achieved through the application of rapid prototyping, tooling and manufacture technologies to provide rapidly configured and reconfigurable tool concepts, for low-cost resin infusion moulding. This article introduces three tooling innovations: reconfigurable tooling concept, variable cavity tooling, and porous cavity tooling.

Recursive polygon offset computing for rapid prototyping applications based on Voronoi diagrams

The generating algorithm of the polygon offsetting is conceptually simple but important, however, geometric problems are very complex. Although some efficient algorithms have been developed to solve it, their computational dependency makes them efficient in only a limited number of line segments of cases. This article presents a recursive algorithm to compute a trimmed offset of a polygon consisting of large-scale line segments in a plane. Assuming that a Voronoi diagram of the polygon is obtained and available, the algorithm constructs topological structures of all Voronoi edges and Voronoi objects: every edge is associated with two Voronoi objects; one object of the Voronoi diagram constitutes the edges. Once the offsetting process starts and intersects with the Voronoi edge of one object, find the next Voronoi object using the topology relation and compute the pairwise intersection in edge. After the rapid prototyping scanning process method has been applied, the result shows that the algorithm is simple and efficient.

In Situ Nanoliter-Scale Polymer Fabrication for Flexible Cell Patterning

Drug-testing technologies, biosensor fabrication, tissue engineering, and basic biological research depend strongly on the patterning of live animal cells. Current techniques for controlling cellular adhesion are restricted with two primary limitations. Firstly, the complexity of the available patterns is very limited and, secondly, the pallet of materials that induce cellular patterning is exhaustible. Here, we demonstrate a method for computer-aided control of cell patterning using a scientific inkjet printer that yields a highly complex cellular pattern suitable for applications in regenerative medicine and rapid prototyping, and a strategy for using in situ polymerization for fabrication polymeric patterns directly on-chip.

Modified Animal Model and Computer-Assisted Approach for Dentoalveolar Distraction Osteogenesis to Reconstruct Unilateral Maxillectomy Defect

The purpose of this report is to show the establishment of an animal model with a unilateral maxilla defect, application of virtual reality and rapid prototyping in the surgical planning for dentoalveolar distraction osteogenesis (DO). Two adult dogs were used to develop an animal model with a unilateral maxillary defect. The 3-dimensional model of the canine craniofacial skeleton was reconstructed with computed tomography data using the software Mimics, version 12.0 (Materialise Group, Leuven, Belgium). A virtual individual distractor was designed and transferred onto the model with the defect, and the osteotomies and distraction processes were simulated. A precise casting technique and numeric control technology were applied to produce the titanium distraction device, which was installed on the physical model with the defect, which was generated using Selective Laser Sintering technology, and the in vitro simulation of osteotomies and DO was done. The 2 dogs survived the operation and were lively. The osteotomies and distraction process were simulated successfully whether on the virtual or the physical model. The bone transport could be distracted to the desired position both in the virtual environment and on the physical model. The novel method to develop an animal model with a unilateral maxillary defect was feasible, and the animal model was suitable to develop the reconstruction method for unilateral maxillary defect cases with dentoalveolar DO. Computer-assisted surgical planning and simulation improved the reliability of the maxillofacial surgery, especially for the complex cases. The novel idea to reconstruct the unilateral maxillary defect with dentoalveolar DO was proved through the model experiment.

Powder particle temperature distribution in laser deposition technologies

PurposeThe purpose of this paper is to provide a flexible tool to predict the particle temperature distribution for traditional laser applications and for the most recent diode laser processes. In the past few years, surface processing and rapid prototyping applications have frequently implemented the use of powder delivery nozzles and high power fibre‐coupled diode lasers with highly convergent laser beams. Owing to the complexity and variety of the process parameters involved in this technology, mathematical models are necessary to understand and predict the deposition behaviour. Modeling the dynamics of the melting pool and the particle temperature distribution is critical for achieving a good deposition quality.Design/methodology/approachThis study focuses on the development of mathematical models to predict the particle temperature distribution over the melting pool. An analytical and a numerical solution are proposed for two cases of laser intensity distribution: top hat and Gaussian.FindingsThe results show that a more vertical position of powder delivery nozzle will lead to a higher and more uniform particle temperature distribution, in particular for the top‐hat intensity distribution case.Originality/valuePrevious work has dealt only with Gaussian laser spatial distributions and collimated laser beams. Therefore, they were limited to a specific class of laser processes. This work provides a flexible tool to predict the particle temperature distribution for traditional laser applications (powder delivery nozzle and Gaussian laser profile) and for the most recent diode laser processes (powder delivery nozzle and top‐hat laser distribution with highly convergent laser beam). In addition, the results demonstrate that the particle temperature does not monotonically increase while increasing the nozzle inclination as in the case of a collimated laser beam, but some particles show a minimum temperature for intermediate values of the nozzle inclination angle.

Rapid Prototyping and Engineering Applications: A Toolbox for Prototype Development

Rapid Prototyping and Engineering Applications: A Toolbox for Prototype Development

Application of Rapid Prototyping Technology in Die Making of Diesel Engine

This paper studies engineering applications of rapid prototyping (RP) technology in die making of diesel engine. On demand of product development and die making of, an integrated system of reverse engineering and rapid prototyping (RE/RP) for engineering application is constructed, and effective application of RP technology in die making is thus realized. Taking the casting die for clutch house of diesel engine as an example, this paper studied the engineering application of laminated object manufacturing (LOM) technology in rapid die making and discussed related technologies as parameter setting of temperature and pressure in heat pressing, the matching of laser power and cutting speed of laser, and layout and post treatment of the prototype in RP technology. The casting die manufactured with LOM technology has satisfactory lifetime and is successfully used in 100 rough castings of clutch house for diesel engine. The manufacturing cost for the die is decreased and the production period is shortened.

Application of rapid prototyping and repositioning guide plate in treatment of posttraumatic orbitozygomatic deformity

Background and Objectives: Orbitozygomatic complex is most common fracture site in midfacial region. Any delayed or inappropriate treatment leads to facial deformity. Comminuted fractures and those with bony lose could cause more severe secondary deformity. Correction of such deformity is quite challengeable to surgeons because of no anatomic landmarks for fractures reduction. In this paper, one method was introduced to use three-dimensional (3D) resin skull model and repositioning guiding plate for rectification of orbitozygomatic deformity.

Highly loaded UV curable nanosilica dispersions for rapid prototyping applications

Silica microcomponents are attractive for applications requiring high temperature stability and chemical durability such as in microreactors. Rapid prototyping methods of forming ceramic dispersions hold great potential for manufacturing of microreactors. Stereolithography for example can benefit from highly solid loaded, low viscosity and high transparency dispersions. This article presents the development of >40 vol.%, UV curable transparent silica nanodispersions having viscosities suitable for stereolithography applications. The main parameters enabling these high loading dispersions are minimization of the Van der Waals attractive forces and affinity of monomer end group for the silica surface (e.g. hydrogen bonding). The minimization of the Van der Waals attraction is achieved by refractive index matching of the nanosilica and UV curable acrylate monomers. This results also in highly transparent dispersions having curing depths in the order of 10 mm in the UVA range. The transformation of selected dispersions to self-supporting silica glass sheets through UV curing, debinding and sintering was investigated by TGA/DTA, dilatometry and XRD.

Effect of Modified Titanium Dioxide on Rheological Behavior of Dental Porcelain Slurries for Rapid Prototyping Applications

AbstractThis study investigates bactericidal activities of dental porcelain contained silver/cerium/titania against streptococcus mutans in different irradiations, then the effect of modified titanium dioxide on rheological behavior of dental porcelain slurries is studied for rapid prototyping applications. The results show that the silver/cerium/titania has much higher antibacterial efficiency than that of pure TiO2 either in the room light or under the dark. It is potential to apply this photocatalyst in the dental materials for preventing human teeth from caries because the oral cavity is mostly under dark, partly in the visible light. The modified titanium dioxide not only has a antibacterial effect, but also can improve the rheological behavior of dental porcelain slurries for rapid prototyping applications.

The Application of Rapid Prototyping for the Design and Manufacturing of Transtibial Prosthetic Socket

This study aims to employ the technology of rapid prototyping for the development of a process that is to assist a prosthetist for easily designing and manufacturing a prosthetic socket for specific transtibial amputee. Currently, the production of prosthetic socket still depends on prosthetists’ skills and expertise. To improve its tedious process, quality uncertainty, and lack of experienced prosthetists, the benefits of using rapid prototyping (RP) technology together with computer-aided systems will be expecting goals. This article demonstrated the feasibility of producing RP sockets using a fused deposition modeling (FDM) machine, and a prototype system that allows a prosthetist to easily design prosthetic sockets has been developed. This proposed computer-aided engineering process, which is plaster-free method, is expected to replace the manual process of conventional approach of fabricating prosthetic sockets. Furthermore, since thin-layer RP socket is easily broken, coating a resin layer on RP socket to enforce its strength is underway.

Automatic 3D shape recovery for rapid prototyping

The capacity to create, display and manipulate a three-dimensional (3D) computer model and produce a physical replica of an existing object, enabling 3D re-shaping activities, plays an important role in different areas such as engineering, biology, architecture and archaeology. Some improvements have been made in a biologically based computer-aided design system, called BioCAD, specifically designed for the rapid and accurate 3D shape recovery from existing large objects, creating 3D computer models either to produce sophisticated photo-realistic renderings, two-dimensional drawings, or to generate surface models for simulation purposes and rapid prototyping applications. This improved system comprises three main routines through which the major findings are as follows: i) the algorithm for “ciliary” calibration routine enables to converge all digital image sequence, so uncertainties decrease, resulting in higher accuracy; ii) through the binocular stereopsis routine, the 3D shape of the perceived large object can actually be inferred; iii) STL and SLI routine allows to integrate BioCAD system and other advanced computer-aided technologies, enabling one to obtain a very small layer thickness from a straightforward slicing process of STL files with a large dimension, minimising the slicing processing time by exploring the advantage of the Matlab language, in terms of matrix manipulation and RAM memory of personal computers.

Particle velocity detection in laser deposition processing

PurposeParticle velocity is a critical factor that can affect the deposition quality in manufacturing processes involving the use of a laser source and a powder‐particle delivery nozzle. The purpose of this paper is to propose a method to detect the speed and trajectory of particles during a laser deposition process.Design/methodology/approachA low‐power laser light sheet technique is used to illuminate particles emerging from a custom designed powder delivery nozzle. Light scattered by the particles is detected by a high‐speed camera. Image processing on the acquired images was performed using both edge detection and Hough transform algorithms.FindingsThe experimental data were analyzed and used to estimate particle velocity, trajectory and the velocity profile at the nozzle exit. The results have demonstrated that the particle trajectory remains linear between the nozzle exit and the deposition plate and that the particle velocity can be considered a constant.Originality/valueThe use of low‐power laser light sheet illumination facilitates the detection of isolated particle streaks even in high‐powder flow rate condition. Identification of particle streaks in three subsequent images ensures that particle velocity vectors are in the plane of illumination, and also offers the potential to evaluate in a single measurement both velocity and particle size based on the observed scattered characteristics. The method provides a useful simple tool to investigate particle dynamics in a rapid prototyping application as well as other research fields involving the use of powder delivery nozzles.

Processing of Bulk Alumina Ceramics Using Laser Engineered Net Shaping

Application of rapid prototyping (RP) in ceramics manufacturing is motivated by advances in engineering ceramics where attaining complex shapes using traditional processing is difficult. Laser Engineered Net Shaping (LENS™), a commercial RP process, is used to fabricate dense, net‐shaped structures of α‐Al2O3. Shapes such as cylinder, cube, and gear have been fabricated successfully with 10–25 mm section sizes. As‐processed structures show anisotropy in mechanical properties with a high compressive strength normal to the build direction and columnar grains along the build direction. Heat treatment did not alter strength and anisotropy, but increased the grain size from 6 to 200 μm and hardness from 1550 to 1700 Hv.

Rapid Prototyping

As the appreciation of structural heart disease in children and adults has increased and as catheter-based closure procedures are now being performed in clinical practice, cardiovascular physicians have multiple compelling new reasons to better understand cardiac anatomic and spatial relationships. Current 2-dimensional imaging techniques remain limited both in their ability to represent the complex 3-dimensional relationships present in structural heart disease and in their capacity to adequately facilitate often complex corrective procedures. This review discusses the cardiovascular applications of rapid prototyping, a new technology that may not only play a significant role in the planning of catheter-based interventions but also may serve as a valuable educational tool to enhance the medical community's understanding of the many forms of structural heart disease.

A Focus On Use

This article analyses the need and benefit of the working of industrial designers and product engineers together. According to engineers and others at the forefront of product development, to do the job right requires a collaboration involving design engineers, industrial designers, manufacturing engineers, and several other players, like marketing people, all of whom have important knowledge that needs to influence a design. Companies such as Trek Bicycle Corp. and Empire Level Manufacturing Corp. have developed practices that foster innovative, human-centered product development. Experts agree that computer-aided design (CAD) and rapid prototyping applications are the two most helpful systems, even though the two types of designers may use the tools in somewhat several ways. According to Rainer Gawlick, vice president of marketing at SolidWorks in Concord, Massachusetts, current CAD systems can help bridge the design-to-engineering-to-manufacturing gap.