Integration Of Rapid Prototyping Research Articles

Rapid prototyping: A future in orthodontic

<abstract> <p>The term “rapid prototyping” (RP) refers to a variety of methods for creating “physical models based on computer-aided design and computer-aided manufacturing”. With the aid of RP technology, practically any variation of the surface and interior anatomical structure may be replicated in a medical model that is constructed layer by layer. To create the physical model, layer-by-layer construction is carried out using a variety of processes, including stereolithography, selective laser sintering, inkjet printing, and fused deposit modeling. Data for RP is received from magnetic resonance imaging and computed tomography scans, which are then turned into digital images and then into standard triangulation language files. The use of this computerized programming in orthodontics incorporates “diagnosis and treatment planning”, the creation of removable “orthodontic appliances”, “impression trays” for indirect bonding, “3D printed occlusal splints and aligners”, prototype models used in various orthognathic surgeries, and the production of a distractor for distraction osteogenesis. It increases a crucial understanding at the time of preoperative treatment planning and raises the effectiveness of the therapy, yet, clinical judgment is still essential. Applications of RP for an orthodontist vary, and if we utilize it creatively, the future appears more hopeful. This article briefly reviews key advancements, challenges, and prospects in the integration of rapid prototyping and 3D printing, shaping a promising future for orthodontics.</p> </abstract>

Flexible liquid‐metal capacitors

Researchers in the US report liquid-metal based tuneable capacitors with linear behaviour and large tuning ratios. Compact and flexible, they hold promise for reconfigurable and wearable RF circuits. The liquid metal research team conducting research at the University of Hawai'i at Manoa. Tuneable capacitors could allow next generation wireless communication systems to adapt to the needs of the user and environment by changing the frequency and bandwidth of RF circuits, optimising their performance in response to the circumstances. Work in tuneable capacitors can be broadly divided into mechanically and electrically controlled approaches. Mechanically controlled capacitors can provide high-power handling, a high Q-factor and often a linear response. However, they tend to be bulkier than electrically controlled capacitors and have a limited tuning range. On the other hand, Electrically-controlled tuneable capacitors tend to have nonlinear behaviour, also limiting their useful range of tuneability. The range of tuneability and the linearity of the change in capacitance are two critical parameters for RF tuneable capacitors. In this issue of Electronics Letters a team at the University of Hawai'i report tuneable capacitors which not only combine linear response with a wide tuning range but add mechanical flexibility, giving them potential in flexible electronics. These benefits derive from their use of liquid metal. “The significance of this work is the integration of rapid prototyping with the dynamic shape-changing characteristics of liquid metal to develop a tuneable element that provides better performance in several categories compared to existing tuneable capacitors,” explains Hawai'i team Member, Prof. Aaron Ohta. “Liquid metal is electrically and thermally conductive, and naturally deformable, allowing it to conform to the shape of its container. Liquid metal can also provide better contact with rough solid surfaces compared to a solid-solid contact. It is also stretchable, enabling its use in flexible electronics. The inherently dynamic behaviour of liquid metal makes it appropriate for reconfigurable electronics.” One of the capacitors they have developed has a tuning ratio of 42:1, and the team say there is potential to increase this. The tuneability of the capacitors is achieved by varying the overlap of parallel conductors, which is an established principle in tuneable capacitors using solid conductors. The key difference in the Hawaii team's approach is that the fluid nature of the liquid-metal conductor allows a wider range of overlap by actuating the liquid metal. Having a large overlap range with solid conductors can easily mean a bulky device; but using liquid metal also allows the team to create reconfigurable conductor shapes that keep the size of the device down. In their Letter, the team present four different geometries, including coils and spirals. The high tuning ratio and linear response of liquid-metal capacitors make them attractive propositions for RF circuits that require a high dynamic range and resolution, such as oscillators, filters, or antennas that need to operate over a wide range of frequency and bandwidth. “In addition, the rapid prototyping of the liquid-metal capacitors described in this Letter is very suitable for laboratory devices,” said Ohta. Left: tuneable liquid metal coil capacitor, formed by a pair of plastic tubes coiled together. One tube is completely filled with liquid metal and the other tube is incrementally filled with liquid metal, providing a tuneable capacitance. Right: The capacitor is attached to a PET substrate, demonstrating its flexibility. The team at the University of Hawai'i are now integrating their tuneable capacitors into various RF circuits including filters, resonators, oscillators and antennas. This includes optimising the frequency response, bandwidth, and loss in each case. They are also working to increase the tuning range of the capacitors and include electrical actuation of the liquid metal for tuning. This is an area in which their group already has significant expertise; having developed several electrical actuation methods to tune networks, phase shifters, switches and antennas. Developing actuation methods for liquid metals that are more easily integrated into common circuit technologies will be critical to seeing this kind of capacitor applied in real-world applications.

Wall-Less Flow Phantoms With Tortuous Vascular Geometries: Design Principles and a Patient-Specific Model Fabrication Example.

Flow phantoms with anatomically realistic geometry and high acoustic compatibility are valuable investigative tools in vascular ultrasound studies. Here, we present a new framework to fabricate ultrasound-compatible flow phantoms to replicate human vasculature that is tortuous, nonplanar, and branching in nature. This framework is based upon the integration of rapid prototyping and investment casting principles. A pedagogical walkthrough of our engineering protocol is presented in this paper using a patient-specific cerebral aneurysm model as an exemplar demonstration. The procedure for constructing the flow circuit component of the phantoms is also presented, including the design of a programmable flow pump system, the fabrication of blood mimicking fluid, and flow rate calibration. Using polyvinyl alcohol cryogel as the tissue mimicking material, phantoms developed with the presented protocol exhibited physiologically relevant acoustic properties [attenuation coefficient: 0.229±0.032 dB/( [Formula: see text]) and acoustic speed: 1535±2.4 m/s], and their pulsatile flow dynamics closely resembled the flow profile input. As a first application of our developed phantoms, the flow pattern of the patient-specific aneurysm model was visualized by performing high-frame-rate color-encoded speckle imaging over multiple time-synchronized scan planes. Persistent recirculation was observed, and the vortex center was found to shift in position over a cardiac cycle, indicating the 3-D nature of flow recirculation inside an aneurysm. These findings suggest that phantoms produced from our reported protocol can serve well as acoustically compatible test beds for vascular ultrasound studies, including 3-D flow imaging.

Hybridized Prototyping Process: A Contemporary Cultural Approach to Enhance Ceramic Production

The development of postmodern theory, are based on contemporary cultural thought and practice. That is; the eclectic mixture of any tradition with that of its immediate. Thus, Postmodernists artists have shown the taste for hybrids, which involves conjoining two different techniques or cultures across the units of time, background and place. This conjunction or creative binding (hybrid) enables the appreciation of both sides of the equation and their union. Therefore, this study employed a deductive and practice-led approach to determine how viable rapid prototyping technology can improve the production process. However, in order to avoid outright elimination of the artisanal skills, the study examines the viability of integrating the conventional skill and modern technology as hybrid technique. The findings from the study revealed that the integration of rapid prototyping and hand-turning (conventional technique) is a viable hybrid production technique that can reduce the development time drastically, enhance product quality and reduce the development cost reasonably in ceramic production.

Selective data acquisition for direct integration of reverse engineering and rapid prototyping

Reverse engineering (RE) has been used closely with rapid prototyping (RP) for fabricating one object from another. Existing RE–RP integrations all begin with the data acquisition of the entire surface of an object. This large point cloud data contains redundancy that must be reduced to avoid unnecessary difficulty in a subsequent surface reconstruction step. Presented in this paper is an alternative approach for direct RE–RP integration. Rather than performing data reduction after capturing the data of an entire object, data are acquired selectively and locally layer by layer. An image-processing algorithm has been developed for recommending the scanning positions based on the part complexity to minimise the number of scans. The result of each scan is contour data points, which can be directly used to generate commands for fabricating a prototype. The implementation of this selective data acquisition approach with a non-contact measuring device is also presented and discussed.

Integration of RP and explicit dynamic FEM for the visualization of the sheet metal forming process

This paper develops a FORTRAN program to convert the explicit dynamic finite element method (FEM)-simulated deformed sheet to the stereolithography (STL) format used in the rapid prototyping (RP) apparatus. Such integration of the RP/FEM can rapidly produce a visualized 3D physical part of the sheet deformation state. Three cases – cylindrical drawing, bore expanding and square cup drawing processes, simulated by explicit dynamic FEM – were investigated to verify the integration system. The wrinkled flange in the cylindrical drawing process, the circle hole expansion in the bore expanding process, and the square cup in the square cup drawing were successfully predicted by explicit dynamic FEM, and the rapid prototyping 3D physical parts also showed good visualization of the deformed sheet for the above three cases. It proves that the integration system of RP/FEM will be able to supply a useful method for the visualization of the 3D physical part in the sheet metal forming process.

Integrated rapid prototyping and rapid tooling (IRPRT)

The strategic integration of rapid prototyping and rapid tooling is being used for getting product to the market quickly by resolving a long‐standing conflict between design and manufacturing. Currently rapid tooling can be produced at such reduced cost and time that the tool is considered to be disposable. The ability to produce inexpensive tooling allows the life cycle to be fundamentally changed, incorporating the concept and tooling review into one development phase and allowing both design and manufacturing requirements to be identified. This approach has allowed management to release product based on competitive market strategy rather than an estimated deadline.

The Potential of Plating Techniques in the Development of Rapid EDM Tooling

Electrodischarge machining (EDM) is a widely used process in the manufacturing of mould cavities for plastic products. EDM work typically accounts for a large portion of overall production time. A major cost and time element of EDM is electrode production, which can account for more than 50% of the total machining costs. A large complex electrode profile, which is very difficult to produce through machining and is also time consuming, can be easily produced using the rapid prototyping (RP) technique. The direct laser sintering of metal powders is a widely established RP process that can be employed for the rapid production of EDM electrodes. In this study, the above-mentioned technique has been employed. The powder mixture used in this process consists of copper, tin, nickel and phosphorus. An infra-red (IR) 200 W CO 2 laser is used to sinter the powdered metals layer-by-layer in order to form solid electrodes. Electroless copper and copper plating are then employed to improve the surface finishing and the conductivity of the sintered electrode as it deposits a uniform thickness of metal onto the substrate by chemical reaction, without building up at the edges and corners, and achieves unique physical characteristics. The performance of the newly developed electrode is very similar to that of conventional copper electrodes. It is found that integration of RP and electroless plating techniques can be a potential means of the rapid production of EDM electrodes at low cost.

The integration of rapid prototyping and CAE in mould manufacturing

In order to shorten the manufacturing time for new products and their moulds, the use and the development of modern techniques are critical. One of such technologies is the rapid prototyping method, which enables the designer and the customer to see the physical presentation of a new product which will be ready for marketing in the period of 3–6 months, already at the early stage of its development. During this period of 3–6 months, the mould must be manufactured and the product must be placed to the market. In this comprehensive R&D work, modern computer techniques must be applied. With the help of computer aided numerical simulations, solving of the greater part of the problems that can emerge during the product and/or mould manufacturing can be predicted. This paper is a result of the co-operation between three Slovenian companies in the development of new products. It starts with the rapid prototyping and computer simulations in the development phase of the product. The same CAE approach will be used in the implementation of modern mould manufacturing techniques, the whole development of the products being treated as an industrial implementation of concurrent engineering methods.

Integration of Rapid Prototyping and Electroforming for Tooling Application

Solid freeform fabrication integrated with electroforming as a novel process for the generation of metal molds and EDM electrodes is presented in this paper. A part built by stereolithography is metalized by electroless plating and then placed in an electroplating solution where metal is deposited upon the part by electrolysis. After the desired thickness of metal has been reached, the part is removed from the metal shell by heating. The shell is then backed with other materials to form a mold cavity or an EDM electrode. The accuracy of the formed mold cavity or EDM electrode influenced by materials and process parameters is discussed.