R. Ian Campbell

Design for Additive Manufacturing: Trends, opportunities, considerations, and constraints

The past few decades have seen substantial growth in Additive Manufacturing (AM) technologies. However, this growth has mainly been process-driven. The evolution of engineering design to take advantage of the possibilities afforded by AM and to manage the constraints associated with the technology has lagged behind. This paper presents the major opportunities, constraints, and economic considerations for Design for Additive Manufacturing. It explores issues related to design and redesign for direct and indirect AM production. It also highlights key industrial applications, outlines future challenges, and identifies promising directions for research and the exploitation of AM’s full potential in industry.

Comparing additive manufacturing technologies for customised wrist splints

Purpose – The purpose of this paper is to compare four different additive manufacturing (AM) processes to assess their suitability in the context of upper extremity splinting. Design/methodology/approach – This paper describes the design characteristics and subsequent fabrication of six different wrist splints using four different AM processes: laser sintering (LS), fused deposition modelling (FDM), stereolithography (SLA) and polyjet material jetting via Objet Connex. The suitability of each process was then compared against competing designs and processes from traditional splinting. The splints were created using a digital design workflow that combined recognised clinical best practice with design for AM principles. Findings – Research concluded that, based on currently available technology, FDM was considered the least suitable AM process for upper extremity splinting. LS, SLA and material jetting show promise for future applications, but further research and development into AM processes, materials an...

A comparative evaluation of industrial design models produced using rapid prototyping and workshop‐based fabrication techniques

This paper discusses a research programme in which the 3D computer aided industrial design geometry for a consumer product was translated into appearance models using the contrasting techniques of workshop‐based fabrication techniques and rapid prototyping using stereolithography. The research also examined the capacity to extend the use of the rapid prototype components for the production of a fully working prototype. The ability to combine an appearance model and a working prototype into a single “appearance prototype” was a significant advance in the application of RP within industrial design.

The Potential for the Bespoke Industrial Designer

Through the combination of innovative and emerging design and manufacturing technologies, a new bespoke industrial design methodology is emerging whereby there will be the ability for individuals to cost effectively control the design and manufacture of individual customized products. The use of novel design devices such as haptic modelling systems that can be used to create a customized three-dimensional model of a desired object, and the subsequent ability to three-dimensionally ‘print’ the design via rapid manufacturing technologies, will see the emergence of a breed of bespoke industrial designer. This paper introduces research work being undertaken at Loughborough University that is investigating these technologies and the effects and opportunities that they will have on the design and manufacturing community.

Computer-aided design to support fabrication of wrist splints using 3D printing: a feasibility study

Introduction Issues contributing to poor patient compliance for splint wear include poor aesthetics, fit and performance. This paper describes a novel digitised splinting process using 3D printing in an attempt to overcome these issues. The output of the investigation was the creation of a specialised computer-aided design software workflow to support 3D printing, developed specifically for splinting practitioners in the UK, to enable them to design splints themselves for each individual patient. Method A small-scale feasibility study was done, based on the current splinting process. A thorough literature review and physical engagement in current splinting practice was performed, highlighting key requirements for successful splint fabrication. Key requirements were then replicated in a virtual software environment. Opportunities for integrating new, novel features were explored. The key requirements were then refined into a specialised software workflow to replicate the splinting process. The specialised software was then evaluated by 10 practitioners. User trials of the software were performed, followed by semi-structured interviews. Audio recordings were transcribed and then coded to establish similar trends of opinions, and areas for future research. No patients or vulnerable participants were involved in the study. Results All participants were able to use and navigate around the software prototype with relative ease. Strengths included potential simplicity in modelling more complex splints, but several areas for future research are identified, including cost analysis and materials development. Discussion The digitised splinting process shows promise for the benefit of both practitioners and their patients, provided that future research and investment can overcome current limitations.

Internet-Based Design Visualization for Layered Manufacturing

When considering the use of layered manufacturing (LM), there are many issues a designer has to address for handling a stereolithography tessellation language (STL) model, the de facto standard for LM. In this paper, we propose an Internet-based design visualization tool for decision support when optimizing the LM process in support of a highly interactive and collaborative virtual environment between CAD designers and LM processes over networks. It directly provides designers with an advanced preprocessor functionality, design visualization/optimization, as well as model display, repair, and slicing over the network. This can help smooth data transfer from CAD to the LM process with minimum inconsistency in CAD data.

Customised design and manufacture of protective face masks combining a practitioner-friendly modelling approach and low-cost devices for digitising and additive manufacturing

This project analyses the viability of an efficient modelling approach using a semi-automatic algorithm within a Computer Aided Design (CAD) application in combination with low-cost digitising devices and low-cost Additive Manufacturing (AM) printers when designing and manufacturing patient-specific face masks. The aims of the study were to enable clinical practitioners to utilise the advantages of three-dimensional (3D) scanning, CAD and AM without having to be trained to use design/engineering software. Face features were captured using two 3D devices. The resulting meshes were compared via the Hausdorff Distance method. A semi-automatic modelling procedure was developed with ‘Rhinoceros’ and ‘Grasshopper’ to model the face mask and customise several features. With that procedure, volunteers modelled a face mask in less than 30 minutes in their first attempt. The resulting virtual mask was manufactured with two AM printers. An initial economic study indicated that the presented approach offers a feasible alternative to the current practices.

Additive manufacturing as an enabler for enhanced consumer involvement

This paper draws on previous work by the authors that aimed to use functional prototypes, produced using additive manufacturing (AM), as a means to draw customer input and preferences into the development of new products. This technique is referred to as Customer Interaction through Functional Prototypes (CIFP). The CIFP philosophy has been proven in both consumer and medical products. In recent years, the authors have developed further concepts of AM-enabled enhanced consumer involvement within their respective research teams. This paper discusses the extended use of CIFP to develop innovative new product concepts in the Vaal University of Technology, to support grant- holders of the Industrial Development’s Corporation (IDC) Support Programme for Industrial Innovation (SPII) and the Technology and Innovation Agency (TIA). The paper goes on to discuss a novel method of consumer interaction developed at Loughborough University, referred to as a Computer-aided Consumer Design (CaCODE). This technique allows non- designers to take an existing product design (e.g., a pen) and modify its shape in real time, in order to create a customised version of the product that meets their needs. The modification is limited within pre-defined parameters to make sure that any final design is functional and can be produced using AM.

Analysis and comparison of wrist splint designs using the finite element method: Multi-material three-dimensional printing compared to typical existing practice with thermoplastics:

Rheumatoid arthritis is a chronic disease affecting the joints. Treatment can include immobilisation of the affected joint with a custom-fitting splint, which is typically fabricated by hand from low temperature thermoplastic, but the approach poses several limitations. This study focused on the evaluation, by finite element analysis, of additive manufacturing techniques for wrist splints in order to improve upon the typical splinting approach. An additive manufactured/3D printed splint, specifically designed to be built using Objet Connex multi-material technology and a virtual model of a typical splint, digitised from a real patient-specific splint using three-dimensional scanning, were modelled in computer-aided design software. Forty finite element analysis simulations were performed in flexion–extension and radial–ulnar wrist movements to compare the displacements and the stresses. Simulations have shown that for low severity loads, the additive manufacturing splint has 25%, 76% and 27% less displacement in the main loading direction than the typical splint in flexion, extension and radial, respectively, while ulnar values were 75% lower in the traditional splint. For higher severity loads, the flexion and extension movements resulted in deflections that were 24% and 60%, respectively, lower in the additive manufacturing splint. However, for higher severity loading, the radial defection values were very similar in both splints and ulnar movement deflection was higher in the additive manufacturing splint. A physical prototype of the additive manufacturing splint was also manufactured and was tested under normal conditions to validate the finite element analysis data. Results from static tests showed maximum displacements of 3.46, 0.97, 3.53 and 2.51 mm flexion, extension, radial and ulnar directions, respectively. According to these results, the present research argues that from a technical point of view, the additive manufacturing splint design stands at the same or even better level of performance in displacements and stress values in comparison to the typical low temperature thermoplastic approach and is therefore a feasible approach to splint design and manufacture.

Visualizing the hotspots and emerging trends of 3D printing through scientometrics

3D printing is believed to be driving the third industrial revolution. However, a scientometric visualizing of 3D printing research and an exploration its hotspots and emerging trends are lacking. This study aims to promote the theory development of 3D printing, help researchers to determine the research direction and provide a reference for enterprises and government to plan the development of 3D printing industry by a comprehensive understanding of the hotspots and trends of 3D printing.,Based on the theory of scientometrics, 2,769 literatures on the 3D printing theme were found in the Web of Science Core Collection’ Science Citation Index Expanded (SCI-EXPANDED) index between 1995-2016. These were analyzed to explore the research hotspots and emerging trends of 3D printing with the software CiteSpaceIII.,Hotspots had appeared first in 1993, grew rapidly from 2005 and peaked in 2013; hotspots in the “medical field” appeared earliest and have remained extremely active; hotspots have evolved from “drug”, “printer”, “rapid prototyping” and “3D printing” in the 1990s, through “laser-induced consolidation”, “scaffolds”, “sintering” and “metal matrix composites” in the 2000s, to the current hotspots of “stereolithography”, “laser additive manufacturing”, “medical images”; “3D bioprinting”, “titanium”, “Cstem cell” and “chemical reaction” were the emerging hotspots in recent years; “Commercial operation” and “fusion with emerging technology such as big data” may create future hotspots.,It is hard to avoid the possibility of missing important research results on 3D printing. The relevant records could be missing if the query phrases for topic search do not appear in records. Besides, to improve the quality of data, this study selected articles and reviews as the research objects, which may also omit some records.,First, this is the first paper visualizing the hotspots and emerging trends of 3D printing using scientometric tools. Second, not only “burst reference” and “burst keywords” but also “cluster” and “landmark article” are selected as the evaluation factors to judge the hotspots and trends of a domain comprehensively. Third, overall perspective of hotspots and trends of 3D printing is put forward for the first time.