Digital Fabrication Technologies Research Articles

A scoping review of digital fabrication techniques applied to prosthetics & orthotics: Part 2 of 2—orthotics

Introduction: Traditionally, orthosis manufacturing is time and labor-intensive. Digitalization of some of the fabrication process is already ubiquitous, yet extension across device types could reduce the burden of manual labor and advance automation to help unblock access to assistive technologies globally. It seems, however, that appropriately strong evidence is holding this back. This review looks to thoroughly examine the current state of evidence to make this clear. Objectives: To identify gaps in the literature that create barriers to decision-making on either appropriate uptake by clinical teams or setting research directions, by identifying what forms of evidence the current research literature provides to the orthotics community. Study design: Scoping literature review. Methods: A comprehensive search was completed in the following databases: AMED, MEDLINE, EMBASE, Global Health Archive, CINAHL Plus, Cochrane Library, Web of Science, ACM, IEEE, and Engineering Village, resulting in 3487 articles to be screened. Results: After screening, 121 lower limb orthosis, 104 upper limb orthosis, and 30 spinal orthosis articles were included in this review. For some areas such as CAD/CAM-produced insoles and spinal orthoses, the evidence base is strong. For most additive manufacture articles, long-term, larger-scale studies as well as research into training requirements are lacking. Conclusion: The advantages of digital fabrication technology that could streamline orthotic device production in many cases are still blocked by a lack of strong formal evidence, ie large longitudinal studies with a range of evaluation measures. Increased collaboration between clinicians, patient/service users, academia, and industry could be a route to addressing these gaps and creating a better pathway to market for new technologies.

Research on the method of digital technology assisted direct resin composite restoration for deep distal caries in mandibular second molars

Objective: To explore the digital design and fabrication technology of personalized restorative matrix for dental filling, and to explore the feasibility of direct resin restoration for deep caries lesions in distal neck of mandibular second molar. Methods: For patients with deep caries lesions in the distal neck of the mandibular second molar who visited the Department of Cariology and Endodontology of Peking University School and Hospital of Stomatology from September 2023 to April 2024, after preparing the cavity and gingival retractor, a three-dimensional intraoral scanner was used to obtain three-dimensional data of the patient's dentition. In the dental restoration computer-aided design software, the inlay function was used to generate the restored tooth morphology. The edge range of the personalized restorative matrix was drawn on the restored model by three-dimensional reverse engineering software to achieve edge sealing effect. The selected edge range data was processed with distal shelling to generate a digital model of a personalized restorative matrix with a thickness of 0.5 mm. A metal three-dimensional printer was used to fabricate the titanium alloy restorative matrix, and its application was completed in 10 clinical cases. The marginal adaptation and retention stability of the personalized restorative matrix were evaluated under a dental microscope, and forming effect evaluation was performed through immediate postoperative periapical radiographs. Results: The preliminary clinical application of the personalized restorative matrix fabricated using digital technology revealed that, in the treatment of 10 affected teeth, rubber dam isolation was successfully ensured, resulting in clinically effective direct resin composite restorations with optimal marginal adaptation and reasonable contours. Immediate postoperative periapical radiographs showed good convexity of the filling body, with no overhangs found. Both marginal adaptation and retention stability met the requirements of clinical treatment. Conclusions: The personalized restorative matrix designed in this study can solve the clinical problems of moisture separation and resin forming in the treatment of deep caries lesions in distal neck of the mandibular second molar, and can achieve stable and reliable adhesive restoration effects.

INTEGRATION OF DIGITAL FABRICATION LABORATORIES AND COMPUTATIONAL DESIGN INTO THE ARCHITECTURE CURRICULUM IN TÜRKİYE

The discipline of architecture undergoes transformation practically, cognitively, and pedagogically due to the widespread use of digital design and fabrication technologies in design processes. This paper aims to eluctade the integration of digital fabrication and computational design with architectural design education at undergraduate level. For this purpose, this study examined the undergraduate course contents and spatial conditions of leading universities with digital fabrication laboratories under three headings: digital design, digital fabrication, and spatial reflections. In addition, this research applied semi-structured interviews with the relevant faculty members of three universities that have robotic tools to obtain more detailed information about their pedagogical approaches. According to this study, the curriculum and laboratories are rapidly changing. As a result, architecture departments are expanding their facilities by building laboratories and tools that have the potential for architectural education to fill the gap between practice and theory. However, there are economic limitations to implementing digital fabrication technologies in terms of the tools and materials used by hundreds of students. This research discusses the requirements, potentials, and limitations of theoretical and practical training through digital fabrication tools that should be included in these courses in the curriculum.

The role of 3- D printing technologies

Digital fabrication technology, often known as 3D printing or additive manufacturing, constructs tangible items by incrementally adding materials based on a geometric model. 3D printing technology is a rapidly advancing technology. Currently, 3D printing finds extensive use worldwide. The agricultural, healthcare, automobile, locomotive, and aviation sectors are increasingly utilising 3D printing technology for mass customisation and manufacturing of various open-source designs. 3D printing technology enables the sequential addition of material layers to create an item directly from a computer-assisted design (CAD) model. This article provides an overview of several kinds of 3D printing methods, their applications, and the materials used in the manufacturing business.Additive manufacturing, 3D Printing, Manufacturing industry

Cement-Based Composites with Additive Manufacturing Technologies for Sustainable Architecture: A Review

To minimize environmental damage caused by architecture and contribute to sustainability, digital fabricationtechnologies, which have lower CO2 emissions and energy consumption compared to traditional productiontechniques, have been applied. One of the processes of digital fabrication is additive manufacturing (AM). AMtechnology is becoming increasingly popular due to its ability to give the designer freedom of form and its eco-friendlynature. Considering the cement-based composites applied with AM technologies, CO2 emissions can be reduced byapproximately 32%. This paper aims to systematically summarize the content, improved properties, andenvironmental advantages of cement-based composite materials applied with AM technology and to determine thedistribution of the number of studies by year. It has been observed that the studies have started to increasesignificantly since 2017. This indicates that cement used in architectural applications through various reinforcementsand, AM technology for environmental sustainability has become more and more widespread.

Knowledge creation through maker practices and the role of teacher and peer support in collaborative invention projects

This study analyzed collaborative invention projects by teams of lower-secondary (13–14-year-old) Finnish students. In invention projects, student teams design and make materially embodied collaborative inventions using traditional and digital fabrication technologies. This investigation focused on the student teams’ knowledge creation processes by examining how they applied maker practices (i.e., design process, computer engineering, product design, and science practices) in their co-invention projects and the effects of teacher and peer support. In our investigations, we relied on video data and on-site observations, utilizing and further developing visual data analysis methods. Our findings assist in expanding the scope of computer-supported collaborative learning (CSCL) research toward sociomaterially mediated knowledge creation, revealing the open-ended, nonlinear, and self-organized flow of the co-invention projects that take place around digital devices. Our findings demonstrate the practice-based, knowledge-creating nature of these processes, where computer engineering, product design, and science are deeply entangled with design practices. Furthermore, embodied design practices of sketching, practical experimenting, and working with concrete materials were found to be of the essence to inspire and deepen knowledge creation and advancement of epistemic objects. Our findings also reveal how teachers and peer tutor students can support knowledge creation through co-invention.

Developing a circular design framework: Co‐creation and validation of a circular product and service design tool

AbstractSustainable products are at the core of the circular economy, which is gaining momentum in scientific, economic, and policy fields. However, existing research in the field of circular product design remains fragmented. The literature has generally tended to focus on material or resource efficiency, while other complex issues related to product ecosystem also exist, such as the needs of the ecosystem (non‐human) and human user, circular challenge, and circular business model. By using a co‐creation approach, this study aims to create and validate a circular product design framework (CD‐Framework) and a self‐assessment tool for circular product design (CD‐Tool) that facilitates an understanding of how product circularity can be improved from the product ideation. The proposed CD‐Framework consists of 10 interconnected categories: circular challenge; circular business model; production; digital fabrication technologies; materials; branding and communication for circularity; packaging, distribution and logistics; user; usage; and after usage. The CD‐Tool was designed as a tool to aid product developers from various industry sectors in the self‐assessment of the circularity of product design. We contribute to developing tools that accelerate integration of circularity into product design through product‐level and ecosystem‐level considerations.

Unlocking the Potential of 3D Printing in Modern Manufacturing

The process of producing tangible items by layering on materials according to geometric representations is called digital fabrication technology, sometimes referred to as additive manufacturing or 3D printing. This innovative technique has gained popularity. Numerous industries, including healthcare, automotive, locomotive, and aviation, now make extensive use of the quickly expanding area of 3D printing technology. This page discusses the materials utilized in the production process, provides a summary of the many types of 3D printing technology, and illustrates the extensive variety of uses for them With the potential to create intricate structures and personalized patterns straight from computer-aided design (CAD) models, 3D printing technology is a potent instrument that has the potential to completely alter the face of contemporary production.

3D Printing and Additive Manufacturing Technology - The Dawn of a New Era!

This Scientific Paper explores the intricate landscape of the fast emerging and rapidly developing 3D Printing, also known as Digital Fabrication technology, spanning and providing an overview of its initial inception, innovation, historical evolution, present day applications across industries, and the various social and environmental implications of its use. This Study highlights the strengths and limitations of the diverse 3D printing technologies and Materials Science, emphasizing their significance in industrial and consumer contexts. The examination of materials underscores their crucial role in determining the quality and functionality of printed objects, with a focus on emerging materials driving innovation. The Study aims to build upon the rich tapestry of historical developments, fundamental principles, and existing research, providing a comprehensive understanding of diverse and manifold 3D printing technologies, analyzing their transformative impact on industries. Furthermore, it carries out an in-depth exploration of challenges, potential solutions, and future directions, aiming to provide insights into the dynamic and versatile nature of 3D printing and Additive Manufacturing technology.

Influence of SiC Doping on the Mechanical, Electrical, and Optical Properties of 3D-Printed PLA

Additive manufacturing, also known as 3D printing or digital fabrication technology, is emerging as a fast-expanding technology for the fabrication of prototypes and products in a variety of applications. This is mainly due to the advantages of 3D printing including the ease of manufacturing, the use of reduced material quantities minimizing material waste, low-cost mass production as well as energy efficiency. Polylactic acid (PLA) is a natural thermoplastic polyester that is produced from renewable resources and is routinely used to produce 3D-printed structures. One important feature that makes PLA appealing is that its properties can be modulated by the inclusion of nano or microfillers. This is of special importance for 3D-printed triboelectric nanogenerators since it can enhance the performance of the devices. In this work we investigate the influence of SiC micron-sized particles on the mechanical, electrical, and optical properties of a PLA-SiC composite for potential application in triboelectric energy harvesting. Our result show that the ultimate tensile strength of the pure PLA and 1%-doped PLA decreases with the number of fatigue cycles but increases by about 10% when SiC doping increases to 2% and 3%, while the strain at max load was about 3% independent of doping and the effective hardness was increased reaching a plateau at about 2 wt% SiC, about 40% above the value for pure PLA. Our results show that the mechanical properties of PLA can be enhanced by the inclusion of SiC, depending on the concentration of SiC. In addition, the same behavior is observed for the dielectric constant of the composite material increases as the SiC concentration increases, while the optical properties of the resulting composite are strongly dependent on the concentration of SiC.

Advanced Manufacturing for Sustainable Fashion. Developing Interdisciplinary Educational Experiences

As a creative industry with high cultural, social, and environmental impacts, Fashion is crucially demanding a paradigmatic shift through digital transformation toward a positive, sustainable change. Therefore, fashion education needs to nurture professionals able to tackle increasingly complex challenges, delving into technological systems and aiming at meaningful environmental, economic, cultural, and societal transformations. New learning paths, approaches, and tools should prepare future fashion designers with a hybrid set of skills placed halfway between design, technology, science, and arts. This paper presents the lessons learned from the Advanced Manufacturing for Sustainable Fashion (ASMF) module conducted at Politecnico di Milano (Design School) in the course Design for the Fashion System. While exploring digital fabrication and smart wearable technologies, students delve into prototyping activities aiming at reflecting on sustainability and fashion design practices’ impacts. The paper describes the used learning tools and approaches and reports on instructional and pedagogical learning outcomes, problems, and future implementation of interdisciplinary educational experiences toward a systemic design paradigm.

Computational reparations as generative justice: Decolonial transitions to unalienated circular value flow

The Latin roots of the word reparations are “re” (again) plus “parere” which means “to give birth to, bring into being, produce”. Together they mean “to make generative once again”. In this sense, the extraction processes that cause labor injustice, ecological devastation, and social degradation cannot be repaired by simply transferring money. Reparations need to take on the full sense of “restorative”: the transition to a decolonial system that can support value generators in the control of their own systems of production, protect the value they create from extraction, and circulate value in unalienated forms that benefit the human and non-human communities that produced that value. With funding from the National Science Foundation, we have developed a research framework for this process that starts with “artisanal labor”: employee-owned business and worker collectives that have people doing what they love, despite low incomes. Focusing primarily on Detroit's Black-owned urban farms, artisanal textile businesses, Black hair salons, worker collectives, and other community-based production, with additional connections to Indigenous and other communities, we have introduced digital fabrication technologies, sensors, artificial intelligence, server-side apps and other computational support for a transition to unalienated circular value flow. We will report on our investigations with the challenges at multiple scales. At each level, we show how computational supports can act as restorative mechanisms for lost circular value flows, and thus address both past and ongoing disenfranchisement.

Planar-thick panels and 3D-printed gap fillers: A hybrid digital fabrication approach to curved surface approximations

Curved surfaces may be approximated using polygonal panels to simplify complex architectural designs, yet their constructions can be expensive due to single-use moulds producing unique panels. To reduce costs, strategies like planarizing and reducing the number of different panels have been suggested, which are increasingly achievable with advancing digital fabrication technologies. However, current subtractive and additive manufacturing techniques face challenges in producing complex 3D shapes and large volumes, respectively. Combining these two techniques has been attempted, mainly with small 3D-printed nodes, leaving the direct realization of curved surface approximations unexplored. This paper extends the thick-panel origami theory to introduce planar-thick panels and 3D-printed gap fillers for cost-effective constructions. It presents a computational workflow to transform meshes into non-intersecting panels while preserving edge connectivity and frame-like gap fillers with minimized volumes. Physical prototypes demonstrate significant cost savings compared to direct 3D printing. All prototypes are accurate within a 10 mm material thickness due to the guidance of the gap fillers. The finite element analysis shows that structural performance is greatly influenced by the material properties, especially of panels, due to their relatively larger volume. Numerical examples are also presented using the k-means clustering-optimization method to reduce the number of different panels.

Seismic performance of Fe-SMA prestressed segmental bridge columns with 3D printed permanent concrete formwork

The integration of digital fabrication technology with prestressed segmental column construction offers significant potential for accelerated bridge construction with material-efficient design. This study aims to explore this potential by developing a novel prestressed segmental column system that utilizes permanent 3D printed concrete (3DPC) formwork for column segment fabrication. Prestressing is achieved in the proposed system by using partially bonded iron-based shape memory alloy (Fe-SMA) reinforcement. Large-scale experiments were conducted on two columns under combined gravity and lateral loading to evaluate the seismic performance and feasibility of the proposed system. The ratio of steel to Fe-SMA reinforcement in the column design was the variable considered in this study. The experimental results showed that the columns could withstand lateral drifts of up to 5% without collapse and the permanent 3DPC formwork showed no premature failure or delamination. Furthermore, the columns exhibited self-centering characteristics, maintaining a residual drift of 1% up to a target drift of 4% when the reinforcement ratio of steel to Fe-SMA rebars was 0.3. The results highlight the potential of the proposed prefabrication concept in designing material-efficient and seismically resilient bridge columns with low damage characteristics.

Digital Fabrication of Segmental Concrete Columns Prestressed with Iron-based Shape Memory Alloy Bars for Accelerated Bridge Construction

The combination of digital fabrication technology and prestressed segmental column construction holds great promise for the accelerated construction of bridges with material-efficient design. This study aims to explore this potential by introducing an innovative prestressed segmental column system that utilizes 3D printed concrete (3DPC) formwork and iron-based shape memory alloy (Fe-SMA) reinforcement for prestressing. To evaluate the proposed system’s performance, large-scale experiments were conducted on two columns subjected to gravity and lateral loads. The experimental findings demonstrated that the columns were capable of withstanding lateral drifts of up to 5% without collapsing, and the 3DPC formwork exhibited no signs of premature failure or delamination. Additionally, the columns displayed self-centering characteristics, maintaining a residual drift of less than 1% up to a target drift of 3%. These results showcase the potential of the proposed prefabrication concept, which can enable the design of bridge columns that are both material-efficient and resilient to seismic actions

Nothing Like Compilation: How Professional Digital Fabrication Workflows Go Beyond Extruding, Milling, and Machines

Understanding how professionals use digital fabrication in production workflows is critical for future research in digital fabrication technologies. We interviewed thirteen professionals who use digital fabrication for the low-volume manufacturing of commercial products. From these interviews, we describe the workflows used for nine products created with a variety of materials and manufacturing methods. We show how digital fabrication professionals use software development to support physical production, how they rely on multiple partial representations in development, how they develop manufacturing processes, and how machine control is its own design space. We build from these findings to argue that future digital fabrication systems should support the exploration of material and machine behavior alongside geometry, that simulation is insufficient for understanding the design space, and that material constraints and resource management are meaningful design dimensions to support. By observing how professionals learn, we suggest ways digital fabrication systems can scaffold the mastery of new fabrication techniques.

Robust optimization for geometrical design of 2D sequential interlocking assemblies

In the realm of sustainable construction within a circular economy, the study of demountable buildings garners significant interest. Achieving the full potential of reusing materials from disassembled structures demands innovative assembly methods surpassing conventional fasteners like nails. Although traditional joinery has addressed this challenge to some extent, it faces design limitations. Modern digital fabrication technologies, such as CNC milling and additive manufacturing, have expanded the horizons for manufacturable assemblies. This paper builds upon prior research to introduce a flexible method for crafting 2D assemblies adaptable to various geometric assumptions. It offers two contributions. Firstly, it provides a versatile numerical model for analyzing the mechanical properties of diverse designs, uncovering novel assemblies with superior mechanical performance compared to traditional configurations. Secondly, it presents an optimization approach enabling precise control over assembly and disassembly of imperfect parts by optimizing joint geometry. By integrating advanced fabrication techniques, adaptable design methods, and mechanical analysis, this research paves the way for the development of sustainable and mechanically efficient demountable buildings.

Out-of-plane shear performance of a novel non-metallic CLT dovetail joint subjected to monotonic and cyclic loading

Timber structures have garnered increasing attention owing to their sustainability and assemblability. Particularly, engineered wood products like cross-laminated timber (CLT) coupled with digital fabrication technologies have promoted the application of traditional mortise-tenon joints in modern mass timber structures. In this paper, a novel non-metallic dovetail joint was proposed to connect the perpendicular CLT wall and lintel. A total of nine specimens were tested under monotonic and cyclic loading to investigate the out-of-plane shear behavior with different widths of the tenon head. The failure modes of the joints were presented, and the mechanical properties including stiffness, strength, ductility and energy dissipation were compared and analyzed. A simplified strength model was developed to evaluate the shear strength of the joint. The experimental results revealed that the specimens mainly failed by timber splitting and crushing under monotonic loading due to the shear force and additional bending moment. The increase in the tenon head width of the dovetail joint from 70 mm to 105 mm resulted in a significant improvement in both stiffness and strength, with enhancements of more than 42 % and 54 %, respectively. All specimens exhibited similar failure modes but more severe timber crushing under cyclic loading. Due to the damage accumulation, the stiffness and strength of the dovetail joint degraded significantly. The specimen with the tenon head width of 84 mm exhibited the highest energy dissipation and relatively low strength degradation under cyclic loading. Additionally, it is recommended to use a ratio of tenon head width to CLT panel thickness at 4/5. The proposed strength model underestimated the load-carrying capacity of the joint generally due to the neglect of the contribution of the bending moment. This study provides base guidelines for the application of dovetail joints in CLT structures.

From Logo Programming to Fab Labs: The Legacy of Constructionist Learning in K−12 Education Technology

Mens et manus, the motto that is embedded in the MIT official seal, is a simple Latin phrase that translates to “mind and hand.” As a continuation of MIT’s pioneering education and research, Seymour Papert, a renowned educator and learning theorist, established the foundation of constructionism, which emphasizes hands-on/minds-on learning. This article explores the evolution of constructionism in K-12 educational technology from the Logo computer language to Scratch block-based programming and the introduction of Fab Labs, which represent the third-generation platform for constructionist teaching and learning. The use of Fab Labs in K-12 education aligns with the Mens et manus philosophy by providing students with opportunities to apply theoretical knowledge to real-world applications through hands-on experiences with digital fabrication technologies. The adoption of the proposed Fab Labs constructionist framework can help prepare students for the demands of a rapidly changing world and aligns with educational standards for science and mathematics.

3D Printer

Digital fabrication technology, also referred to as 3D printing or additive manufacturing, creates physical objects from a geometrical representation by successive addition of materials. 3D printing technology is a fast-emerging technology. Nowadays, 3D printing is widely used in the world. 3D printing technology has been increasingly used for the mass customization, production of any types of open-source designs in the field of agriculture, in healthcare, automotive industry, locomotive industry and aviation industries. 3D printing technology can print an object via layer-by-layer deposition of material directly from Computer Aided Design (CAD) model. This paper presents an overview of the types of 3D printing technologies, the application of 3D printing technology, and the materials used for 3D printing technology in the manufacturing industry.