Additive Manufacturing in Bespoke Interactive Devices—A Thematic Analysis

Round 1

Reviewer 1 Report

This article is  innovative. Please check that the statement is concise and the format is consistent with the journal requirements.

The English level is good, please refine thThe English level is good, please refine the sentences in the articlee sentences in the article.

Author Response

Reviewer Comment 1.1: The English level is good, please refine thThe English level is good, please refine the sentences in the articlee sentences in the article.

Authors’ Comments and Amendments in Manuscript: The quality of the English language was revised.

Reviewer 2 Report

This paper presents a thematic analysis of the " Design for Additive Manufacturing: Future Interactive Devices" workshop, concluding that designers require a cohesive AM design tool to consider AM factors throughout the entire design process. Overall, the paper is acceptable, but there are a few minor issues:

1. What does XXX stand for? Is the name of the workshop confidential? This includes both the project name and the funding name.

2. The quality of the pictures in the text is poor and the layout needs to be improved.

3. The citation style of the references is not consistent, and the order is also confusing. For example, the format of the references in the Materials and Methods section is different from that in other sections.

4. The paper is not written in a very standard manner, and some effort is needed to improve it.

The paper is not written in a very standard manner, and some effort is needed to improve it.

Author Response

Reviewer Comment 2.1: What does XXX stand for? Is the name of the workshop confidential? This includes both the project name and the funding name.

Authors’ Comments and Amendments in Manuscript: The names of the project and workshop were censored to maintain anonymity. The paper has been amended following the review, to include the official names of the project, workshop, and university and industrial partners involved.

Reviewer Comment 2.2: The quality of the pictures in the text is poor and the layout needs to be improved.

Authors’ Comments and Amendments in Manuscript: The pictures have been amended, and the layout of the template provided by the journal was followed. To account for any changes when uploading the final copy of the paper, a pdf version will be uploaded.

Reviewer Comment 2.3: The citation style of the references is not consistent, and the order is also confusing. For example, the format of the references in the Materials and Methods section is different from that in other sections.

Authors’ Comments and Amendments in Manuscript: The citations have been updated accordingly.

Reviewer Comment 2.4: The paper is not written in a very standard manner, and some effort is needed to improve it.

Authors’ Comments and Amendments in Manuscript: The layout and English language used throughout the paper has been revised.

Reviewer 3 Report

In this paper has been shown the conclusion based on the conducted workshops on the usability of AM to manufacturing the bespoke devices. Authors draw their conclusions relaying on the results which are obtained during a two-day workshop.

The conclusions given in this paper are, more or less, well known in the area of AM.  The AM is relatively new technology and currently missing DFAM guidelines. The main problem is that AM is a set of several technologies divided into 6 areas, but designer still AM see as one technology. Because of that we often have a bad use of the technology itself, so it is very important to expand knowledge about AM itself. Regarding that, the conclusions presented in this paper are very important for designers and researchers who work in the AM fields.

1.       The name of the workshop is already given in the abstract, so I would like to remove the XXXX marks in the text and be replaced with DFAM-FID (Design for Additive Manufacturing: Future Interactive Devices). Also, the name of the University involved in this research should be public. (not University XXX)

2.       The numbers in the superscript given in the lines 62-72 and in the following text are not clearly explained.

3.       Line 98 – Figure 1.  It is not clearly explained the integration of the AM guidelines into design process. Please give us a better explanation.

4.        Line 367 - My opinion is that rules for ergonomic design of the bespoken devices should not be a part of the DFAM guidelines. The rules for ergonomics should be a special set of instructions which will be applied in the design process and which must be mandatory in order to create pleasant and usable devices. DFAM guidelines should define a possibility to build devices in chosen AM technology with appropriate process parameters, quality, etc.

5.       Line 462 – In general, every design process is iterative. I think that here is better to say that process of design of bespoken devices is highly iterative, rather than AM design process is iterative. The introduction of new production technology - AM in this process leads to the need to form multidisciplinary teams in order to design bespoken devices.

 

6.       If there is not funding of the project, please remove the funding paragraph.

Author Response

Reviewer Comment 3.1: The name of the workshop is already given in the abstract, so I would like to remove the XXXX marks in the text and be replaced with DFAM-FID (Design for Additive Manufacturing: Future Interactive Devices). Also, the name of the University involved in this research should be public. (not University XXX).

Authors’ Comments and Amendments in Manuscript: The names of the project workshop, and university and industrial partners involved were censored to maintain anonymity, however following the review have been included. The official acronym for the workshop is DEFINED, and has been used throughout the paper to refer to the workshop.

Reviewer Comment 3.2: The numbers in the superscript given in the lines 62-72 and in the following text are not clearly explained.

Authors’ Comments and Amendments in Manuscript: The citation style was altered when uploading the paper for submission, and have been arranged accordingly to fit one style of reference, as per the Author’s Guidelines provided by the journal.

Reviewer Comment 3.3: Line 98 – Figure 1.  It is not clearly explained the integration of the AM guidelines into design process. Please give us a better explanation.

Authors’ Comments and Amendments in Manuscript: According to Laverne et al. (2015), the AM knowledge is used throughout the design process, to generate the concept, CAD model (to be used in 3D printing) and the final additively manufactured prototype.

Reviewer Comment 3.4: Line 367 - My opinion is that rules for ergonomic design of the bespoken devices should not be a part of the DFAM guidelines. The rules for ergonomics should be a special set of instructions which will be applied in the design process and which must be mandatory in order to create pleasant and usable devices. DFAM guidelines should define a possibility to build devices in chosen AM technology with appropriate process parameters, quality, etc.

Authors’ Comments and Amendments in Manuscript: The authors agree with this comment, and have amended the script as follows:

Finally, on a more generalised level, the ergonomic testing results can be incorporated in the design principles knowledge base to better meet user requirements.
Lines 425 – 426

Reviewer Comment 3.5: Line 462 – In general, every design process is iterative. I think that here is better to say that process of design of bespoken devices is highly iterative, rather than AM design process is iterative. The introduction of new production technology - AM in this process leads to the need to form multidisciplinary teams in order to design bespoken devices.

Authors’ Comments and Amendments in Manuscript: A better distinction had to be made between the basic design cycle, and the design for additive manufacturing approach throughout the synthesis phase of the design cycle. Therefore, the following was added to highlight this distinction:

The Basic Design Cycle is a model representing the fundamental steps that a designer undergoes throughout the design process [25]. It consists of a sequence of conscious reasoning steps, which are performed across the phases of a design process. This is an iterative process, starting with the problem analysis. This is followed by the synthesis step, where design concepts are generated. These are then simulated and evaluated, and a decision is made on the most suitable design concept to fulfill the design problem. A systematic approach can be taken during solution analysis in the synthesis phase, to reveal and control how a product interacts with a system. In the context of this research, this approach concerns how a design concept would be manufactured with additive technologies to generate the best interactive device for a patient. The interaction knowledge can be captured to improve a design solution from an AM point of view.
Lines 111 – 121

Reviewer Comment 3.6: If there is not funding of the project, please remove the funding paragraph.

Authors’ Comments and Amendments in Manuscript: The workshop and project have been funded by an external body. The funding paragraph was censored to maintain anonymity throughout the review process. Therefore, this section has been amended to:

6. Funding
   The DEFINED workshop was funded through the research project titled “Personalised Recovery Through A Multi-User Environment: Virtual Reality for Rehabilitation” (PRIME-VR2). PRIME-VR2 was funded by the EU’s Horizon 2020 research and innovation programme under grant agreement N^o 856998. The authors are grateful for the contribution of all the DEFINED workshop participants who provided valuable expertise on the design and manufacture of bespoke VR devices.
   Lines 819 – 824

Reviewer 4 Report

 

Overall, the abstract provides a concise summary of the article. It discusses the advantages of additive manufacturing (AM) for product development and the potential application of AM for fabricating customisable devices, such as bespoke interactive devices for rehabilitation purposes. The article then focuses on a two-day workshop titled "Design for Additive Manufacturing: Future Interactive Devices" that aimed to discuss the design for AM issues encountered in the development of an innovative bespoke controller and supporting platform for people with limited dexterity in their hands. The themes of the workshop were identified through a thematic analysis of the workshop sessions and discussed in relation to available literature.

 

In the text, there are several instances where a workshop titled XXX and a XXX Project are mentioned, it would be beneficial for the authors to provide the real details and their goals, timelines, and participants. This would help to clarify the significance of the workshop and project, as well as provide a stronger foundation for the rest of the article.

 

The introduction could be improved by providing more context and background information on the specific topic being discussed. While the authors briefly mention the advantages of additive manufacturing (AM) over traditional manufacturing methods, they do not provide a clear explanation of what AM is and how it works. Additionally, the article jumps straight into discussing the XXX Project without providing any information on why this project is significant or what motivated it. Providing more context on the significance of the XXX Project and the potential impact of AM on the medical field would help to engage the reader and create a stronger foundation for the rest of the article.

 

The Material and Method section should be improved. Be specific and clear: Make sure to clearly outline the steps taken to conduct the analysis or review. Provide specific details on the inclusion/exclusion criteria, the software used, and the methodology. This will make it easier for readers to understand and potentially replicate the study.

 

The figures should be uploaded in a better resolution 

The Results section is really difficult to follow it. 

 

The Discussion section provides a good summary of the main outcomes of the workshop and how they relate to the use of AM in the production of bespoke interactive devices. The authors highlight the importance of customization in these devices and how AM is well-suited for their production due to its inherent flexibility.

 

To improve the section, the authors could expand on the specific implications of their findings. For example, how might the lack of DFAM guidelines affect the adoption of AM in large-scale production processes? What are the specific skills that designers need to acquire to effectively adopt AM technologies? Providing more concrete examples and recommendations would make the discussion section more informative and actionable for the reader.

 

Additionally, the authors could provide more context on the existing literature in this area. While they mention a few studies that have shown knowledge about AM opportunities is limited, they do not provide any further details on these studies or how their findings relate to the outcomes of the workshop. Including more literature citations and contextual information would help the reader to better understand the significance of the workshop outcomes in the broader field.

 

Author Response

Reviewer Comment 4.1: In the text, there are several instances where a workshop titled XXX and a XXX  Project are mentioned, it would be beneficial for the authors to provide the real details and their goals, timelines, and participants.   This would help to clarify the significance of the workshop and project, as well as provide a stronger foundation for the rest of the article.

Authors’ Comments and Amendments in Manuscript: The names of involved universities, industrial partners, projects, and workshop were censored to maintain anonymous for the reviewing process. The following was added to highlight the significance of the project:

Within this context, the project titled “Personalised Recovery through a Multi-User Environment: Virtual Reality for Rehabilitation” (PRIME-VR2), aimed to deliver a VR controller, fabricated with AM, which is purposely designed according to the person’s needs for rehabilitation purposes, rather than using an off-the-shelf device. The tailor-made wearable controller has been developed for three target users, namely persons who suffered a sports injury, post-stroke patients, and children with dystonia (suffering involuntary hand movements). The main reasons to adopt a VR-based rehabilitation are to reduce the duration of the therapy programme and to engage more the aforementioned user groups in the therapy, compared to the current traditional clinical practices.
Lines 58 – 66

The following has been added to the paper to provide more information about the workshop:

Over a period of two days, eight workshops lasting on average an hour each were hosted, to address the multidisciplinary approach to the design of future interactive devices manufactured though AM. A total of 61 academics and 34 industrialists, with a range of between two and thirty years of experience, and familiar with the AM de-sign and process attended the workshop.
Lines 344 – 348

Reviewer Comment 4.2: The introduction could be improved by providing more context and background information on the specific topic being discussed. While the authors briefly mention the advantages of additive manufacturing (AM) over traditional manufacturing methods, they do not provide a clear explanation of what AM is and how it works.

Authors’ Comments and Amendments in Manuscript: The following has been added to the introduction, to provide some context to the paper:

The ISO/ASTM 52900 terminology standard defines Additive Manufacturing (AM) as a bottom-up technique which fuses materials to build a physical product, starting from a virtual 3D model with material being introduced to ‘print’ the equivalent physical product layer upon layer, as opposed to subtractive and formative manufacturing processes. In recent years, AM has brought advancements in manufacturing and product development. This is due to the various advantages of AM compared to conventional top-down fabrication techniques, including a shorter time-to-product, production on demand, low costs for small lot sizes, improvements in product functionality, and greater freedom in design [1–5].
Lines 29 – 37

Virtual Reality (VR) technology has existed for over thirty years, but in recent years it gained popularity in various sectors. The dominant VR market is the entertainment world, notably in gaming. However, due to its advantages, in particular enhancing the visualization experience of the user, VR is being applied in other sectors including manufacturing, maintenance, cultural heritage, architecture, and healthcare. Regarding the latter, VR is being exploited for surgical intervention training and rehabilitation. Irrespective of the application, a device, similar to a gaming console, is required to enable users to play a ‘serious’ game in an interactive and immersive VR environment. The primary purposes of a serious game goes beyond pure entertainment, such as for rehabilitation purpose. However, most VR-based applications use an off-the-shelf controller, which for a certain category of end-users with limited hand and finger dexterity, may not be sufficiently comfortable to use.
Lines 46 – 57

Reviewer Comment 4.3: The Material and Method section should be improved. Be specific and clear: Make sure to clearly outline the steps taken to conduct the analysis or review. Provide specific details on the inclusion/exclusion criteria, the software used, and the methodology. This will make it easier for readers to understand and potentially replicate the study.

Authors’ Comments and Amendments in Manuscript: The methodology adopted for the thematic analysis and literature review are now explained with the amended text:

A thematic analysis aims at identifying patterns or ‘themes’ across a data set. One advantage of this method is its high flexibility [13,14]. The methodology adopted in the thematic analysis starts with the familiarisation of the data. This is followed by the generation of the initial codes, where the themes are identified, reviewed, and defined [15]. However, thematic analysis may be too flexible since it is subjective, leading to inconsistencies in the developed themes [16]. Thus, results were validated through a reliability study.
Lines 77 – 83

The literature review, focused on relevant studies to the “design process of additive manufactured products”, “user experience (UX) and user-centred design (UCD)”, and “bespoke additive manufactured interactive devices”, was conducted to further deepen the understanding of basic principles discussed throughout the workshop. International scientific articles from journals and conferences from the last 20 years were reviewed. The databases of Pubmed, ScienceDirect, and Google Scholar were used with the aforementioned keywords. Duplicate articles, and those not written in English were excluded. Considering these exclusion criteria, 64 articles were selected.
Lines 97 – 104

Reviewer Comment 4.4: The figures should be uploaded in a better resolution.

Authors’ Comments and Amendments in Manuscript: The figures have been upgraded to a higher resolution.

Reviewer Comment 4.5: To improve the section, the authors could expand on the specific implications of their findings. For example, how might the lack of DFAM guidelines affect the adoption of AM in large-scale production processes? What are the specific skills that designers need to acquire to effectively adopt AM technologies? Providing more concrete examples and recommendations would make the discussion section more informative and actionable for the reader. Additionally, the authors could provide more context on the existing literature in this area. While they mention a few studies that have shown knowledge about AM opportunities is limited, they do not provide any further details on these studies or how their findings relate to the outcomes of the workshop. Including more literature citations and contextual information would help the reader to better understand the significance of the workshop outcomes in the broader field.

Authors’ Comments and Amendments in Manuscript: A study conducted by Pradel et al. (2018) has been explained in the following, to provide some motivation to why design guidelines and tools are needed, which was one of the outcomes of the workshop:

Pradel et al. (2018) conducted a survey with 110 designers and semi-structured interviews with 18 designers [28]. The authors found that typically, designers view AM as a prototyping tool, rather than for end-use products. They noted that AM is most frequently used to produce consumer goods and medical devices. Finally, the authors found that designers grouped all AM processes under a homogenous group, even though these processes have different capabilities. It is essential that designers have the knowledge of different AM processes, their operating principles, their characteristics, and their limitations, to effectively deliver products of high quality. Guidelines should be more accessible, for designers to be able to optimise the design concept for the AM constraints.
Lines 168 – 176

The implications of the results of this paper have been highlighted in the discussion, which stated:

In this context, it can be seen that customisation is essential in bespoke interactive devices, which need to conform to the patient’s body for a comfortable fit and thus promote adherence to therapy. AM is ideal for the production of wearable devices in low quantities, due to its inherent flexibility compared with traditional manufacturing processes.
Traditional manufacturing processes have a lengthy history in industry, resulting in established standards and guidelines. The main outcome of the DEFINED workshop is that there is not a variety of DFAM guidelines available, and that there is a need for greater education in the sector. Many current engineers lack knowledge in both AM and traditional manufacturing, resulting in a difficult adoption path for AM in large scale production processes. New design for manufacturing education and processes are needed to support the adoption of the strengths of the AM processes while not benchmarking performance against traditional manufacturing processes standards. This complies with studies which show that due to recent developments in AM, knowledge about its opportunities is limited [28,29,77,90–92]. To effectively adopt AM technologies, designers will be required to acquire 3D modelling skills to enhance user outcomes [81], otherwise they will struggle with managing design procedures [93].
Another outcome of this workshop was the need for a coherent DFAM tool to guide designers when taking AM considerations in their design practices. This result differs from the study conducted by Kumke et al. [1], which states that the designer’s individual preference and experience require that a variety of DFAM tools should be available.
Lines 750 – 770

However, the following was added to further emphasise the outcomes of the workshops, and its context in literature and practice:

These tools will help the designer to develop following skills which emerged from literature and the workshops, to facilitate design of Additive Manufacturing of Bespoke Interactive Devices:
• knowledge of 3D acquisition methods;
• knowledge of tools for the free-from computational approach;
• a more in-depth knowledge of the various additive manufacturing techniques (e.g. VAT - high resolutions, but the possibility of using a single material, problems such as suction cups, tilting of flat surfaces, mechanical removal of supports; Material Extrusion - high availability of materials, low cost, but lower resolutions, warping problems, etc.; Powder Bed Fusion - less need for supports, but warping and internal stress issues and powder trapping problems in channels, etc.);
• greater understanding of the properties of materials machined with AM (e.g. anisotropy, higher roughness, etc.);
• greater interdisciplinarity, soft skills and ability to manage complexity by dealing with/interacting with different fields (e.g. manufacturing, materials, computational approaches, electronics, knowledge of regulations, aspects related to ergonomics and a basic knowledge of the medical field).
Lines 770 – 787

Reviewer 5 Report

Summary:

This manuscript discusses results from a two-day workshop focused on how additive manufacturing can be integrated with other technologies to develop interactive devices tailored for people with limited dexterity in their hands. The complementary technologies included generative design algorithms, user-controlled design, measurement devices for data acquisition, virtual reality, augmented reality, and haptics. The most interesting feature of this work is that it presents the current discussions and paths forward for efficiently integrating these technologies to improve interactive device manufacturing. One of the key findings is that due to the lack of an informed workforce, a “Design for Additive Manufacturing” tool is needed. Although this highly interdisciplinary work is impactful, it could benefit from minor revisions.

Comments

Abstract:

1.       The first sentence needs to be edited to improve clarity.

2.       The first “and” needs to be removed from line 21.

Introduction:

1.       “XXX” appears several times in the introduction and throughout the work. These need to be updated. Why were these titles omitted from the initial submission?

2.       The last paragraph of the Introduction is unnecessary.

Materials and Methods:

1.       Significantly more information describing the ICR is needed. What does “codes” mean on line 65? How many “coders” were used? What are the “coders” backgrounds?

Results

1.       Line 91 appears to be missing some words after “…components or designing new.”

2.       The paragraph starting on line 188 does not clearly explain Figure 2. What is the figure trying to convey with the mirrored triangles?

3.       One thing that may be noted in comparing Figure 3 to Figure 4 is that the digital nature of additively manufactured parts makes iteration much easier, allowing for the arrow between “Assessment” and “Users.” Figure 4 does not make a complete circle of arrows, meaning iteration using traditional manufacturing is not as straightforward.

4.       What is “This” referring to on the start of line 227?

5.       The discussion of the “workshops” in section 3.2 seem better suited for the “Materials and Methods” section.

6.      In line 408, the authors state that topological optimization produces parts with “equivalent strength to weight ratios.” However, the point of topological optimization in this context is to IMPROVE strength to weight ratios.

Some typos and incomplete thoughts exist in the work, but can be corrected with minor editing.

Author Response

Reviewer Comment 5.1: Abstract: (1) The first sentence needs to be edited to improve clarity; (2) The first “and” needs to be removed from line 21.

Authors’ Comments and Amendments in Manuscript: The abstract has been updated accordingly. 

Reviewer Comment 5.2: Introduction: (1) “XXX” appears several times in the introduction and throughout the work. These need to be updated. Why were these titles omitted from the initial submission? (2) The last paragraph of the Introduction is unnecessary.

Authors’ Comments and Amendments in Manuscript: (1) The names of the projects, workshop, and universities and industrial partners involved were omitted from the initial submission of the paper, to maintain anonymity throughout the review process; (2) The last paragraph of the Introduction gives an overview of the paper. This was included as it was seen in other journal papers published by Applied Sciences.

Reviewer Comment 5.3: Materials and Methods: (1) Significantly more information describing the ICR is needed. What does “codes” mean on line 65? How many “coders” were used? What are the “coders” backgrounds?

Authors’ Comments and Amendments in Manuscript: (1) The authors agree and the following text was added:

Two coders performed the thematic analysis, where the main coder’s area of research is not in AM. Therefore an inductive approach was taken, since the thematic analysis by the main coder was conducted prior to the literature review. This results in identifying data-driven themes, which are strongly linked to the data, without trying to fit into a pre-existing coding framework [15,19]. The second coder had an established background in AM research. This results in a deductive approach, whereby it is driven by the researcher’s interpretation of concepts. This reduces any bias that would have been present if the same approach was used by both coders to code the data.
Lines 84 – 92

Reviewer Comment 5.4: Results: (1) Line 91 appears to be missing some words after “…components or designing new.”; (2) The paragraph starting on line 188 does not clearly explain Figure 2. What is the figure trying to convey with the mirrored triangles?; (3) One thing that may be noted in comparing Figure 3 to Figure 4 is that the digital nature of additively manufactured parts makes iteration much easier, allowing for the arrow between “Assessment” and “Users.” Figure 4 does not make a complete circle of arrows, meaning iteration using traditional manufacturing is not as straightforward; (4) What is “This” referring to on the start of line 227?; (5) The discussion of the “workshops” in section 3.2 seem better suited for the “Materials and Methods” section; (6) In line 408, the authors state that topological optimization produces parts with “equivalent strength to weight ratios.” However, the point of topological optimization in this context is to IMPROVE strength to weight ratios.

Authors’ Comments and Amendments in Manuscript: (1) The following was added:

Assembly-based DFAM (A-DFAM) intends on improving the product architecture by reducing the number of components or designing new devices.
Lines 133 – 135

(2) The following text was added:

This is shown in Figure 2, where the established consumer requirements influence the design concepts in a DWX approach. When applying DFX, the design concepts are adapted to meet the consumer’s needs to generate an innovative solution.
Lines 236 – 239

(3) The authors agree and appreciate this observation, and have added the following:

Finally, the workflow shown in Figure 3 is cyclic, whereby the digital nature of AM devices allows for user feedback to be easily integrated in the design. In Figure 4, the workflow is linear, inferring that iteration is not as easily achievable with traditional manufacturing.
Lines 269 – 272

(4) The authors have amended the text as follows:

The limitations of the conventional prosthesis fabrication process provides an opportunity for the design of medical devices to be improved through computer technologies [79], as demands for manufacturing techniques, which can be fabricated according to end-user and medical tolerances [80], are increasing.
Lines 285 – 288

(5) The discussion of the workshops was added to the Results section to give context to the thematic analysis.

(6) The text has been updated as follows:

Through topological optimisation, shapes can be easily and cost effectively produced with improved strength to weight ratios.
Lines 465 – 466

 

Round 2

Reviewer 4 Report

My suggestions for improving the article were adopted by the authors and I recommend publishing it.