3D printing of biofiber-reinforced composites and their mechanical properties: a review

Recent advances in 3D printing technologies for wearable (bio)sensors

Graphene is an important nanocarbon nanofiller for polymeric matrices. The polymer–graphene nanocomposites, obtained through facile fabrication methods, possess significant electrical–thermal–mechanical and physical properties for technical purposes. To overcome challenges of polymer–graphene nanocomposite processing and high performance, advanced fabrication strategies have been applied to design the next-generation materials–devices. This revolutionary review basically offers a fundamental sketch of graphene, polymer–graphene nanocomposite and three-dimensional (3D) and four-dimensional (4D) printing techniques. The main focus of the article is to portray the impact of 3D and 4D printing techniques in the field of polymer–graphene nanocomposites. Polymeric matrices, such as polyamide, polycaprolactone, polyethylene, poly(lactic acid), etc. with graphene, have been processed using 3D or 4D printing technologies. The 3D and 4D printing employ various cutting-edge processes and offer engineering opportunities to meet the manufacturing demands of the nanomaterials. The 3D printing methods used for graphene nanocomposites include direct ink writing, selective laser sintering, stereolithography, fused deposition modeling and other approaches. Thermally stable poly(lactic acid)–graphene oxide nanocomposites have been processed using a direct ink printing technique. The 3D-printed poly(methyl methacrylate)–graphene have been printed using stereolithography and additive manufacturing techniques. The printed poly(methyl methacrylate)–graphene nanocomposites revealed enhanced morphological, mechanical and biological properties. The polyethylene–graphene nanocomposites processed by fused diffusion modeling have superior thermal conductivity, strength, modulus and radiation- shielding features. The poly(lactic acid)–graphene nanocomposites have been processed using a number of 3D printing approaches, including fused deposition modeling, stereolithography, etc., resulting in unique honeycomb morphology, high surface temperature, surface resistivity, glass transition temperature and linear thermal coefficient. The 4D printing has been applied on acrylonitrile-butadiene-styrene, poly(lactic acid) and thermosetting matrices with graphene nanofiller. Stereolithography-based 4D-printed polymer–graphene nanomaterials have revealed complex shape-changing nanostructures having high resolution. These materials have high temperature stability and high performance for technical applications. Consequently, the 3D- or 4D-printed polymer–graphene nanocomposites revealed technical applications in high temperature relevance, photovoltaics, sensing, energy storage and other technical fields. In short, this paper has reviewed the background of 3D and 4D printing, graphene-based nanocomposite fabrication using 3D–4D printing, development in printing technologies and applications of 3D–4D printing.

Critical appraisal and systematic review of 3D & 4D printing in sustainable and environment-friendly smart manufacturing technologies

Shape memory polymers are smart materials that produce shape changes under external stimulus conditions. Four-dimensional (4D) printing is a comprehensive technology originate from deformable materials and three-dimensional (3D) printing technology. At present, 4D printed shape memory polymers and shape-changing structures have been applied in various fields, especially in the field of biomedical science. 4D printing technology has made a breakthrough of personalized customization in the traditional medical field, providing a new direction for the further development of the biomedical field. In this review, the recent research and development of shape memory polymer, 3D printing technology, 4D printed shape memory polymers and shape-changing structures in biomedical area are present. The examples and applications of 4D printed shape memory polymers and their structures in the area of biomedical are also introduced. Based on 4D printing, stimulated by different conditions, 3D printed objects can be fabricated into various biomedical applications such as cell scaffolds, vascular stents, bone scaffolds, tracheal stents and cardiac stents by different 3D printing techniques. Finally, the application prospects, existing technical restriction and future development directions of 4D printed shape memory polymers and their structures in the biomedical field are summarized.

Over the last two decades, researchers, technologists, designers, and manufacturers have made enormous efforts to commercialize additive manufacturing (AM) or 3D printing technology in an array of fields including textile, apparel, and fashion industries. Recently, a great advancement in AM of complex architectures, which are impossible or difficult to produce otherwise, has been reported. Following the success of making metal/polymer-based 3D printed stiff structures, researchers have also explored the potential of this technique for creating flexible materials such as smart textiles. This chapter presents 3D printing as a novel method for the manufacturing of more flexible, cost-effective, and functional textiles via techniques such as screen printing and ink-jet printing and for fabricating smart textile structures which are slightly different from the conventional knitted or woven fabrics but possessing intelligent properties. Specifically, in this chapter, an overview of 3D printing technology, different 3D printing techniques, material selection, and properties of 3D printed objects in the context of manufacturing of smart and functional textiles is discussed. Emerging smart textiles enabled by 4D printing have also been explored which can exhibit transformation in their structure or colour as a function of time in the presence of an external stimulus. Therefore, the transition from 3D to 4D printing, the basic aspects of 4D printing, and materials selection for 4D printing of smart textiles and fashion products are presented here. The subsequent section discusses the potential applications of textiles enabled by 3D and 4D printing. Finally, current challenges and future perspectives of 3D and 4D printing of smart textiles are summarized.

Owing to COVID-19, the world has advanced faster in the era of the Fourth Industrial Revolution, along with the 3D printing technology that has achieved innovation in personalized manufacturing. Three-dimensional printing technology has been utilized across various fields such as environmental fields, medical systems, and military materials. Recently, the 3D food printer global market has shown a high annual growth rate and is a huge industry of approximately one billion dollars. Three-dimensional food printing technology can be applied to various food ranges based on the advantages of designing existing food to suit one’s taste and purpose. Currently, many countries worldwide produce various 3D food printers, developing special foods such as combat food, space food, restaurants, floating food, and elderly food. Many people are unaware of the utilization of the 3D food printing technology industry as it is in its early stages. There are various cases using 3D food printing technology in various parts of the world. Three-dimensional food printing technology is expected to become a new trend in the new normal era after COVID-19. Compared to other 3D printing industries, food 3D printing technology has a relatively small overall 3D printing utilization and industry size because of problems such as insufficient institutionalization and limitation of standardized food materials for 3D food printing. In this review, the current industrial status of 3D food printing technology was investigated with suggestions for the improvement of the food 3D printing market in the new normal era.

The development of patient-specific prosthetics, medication administration, the manufacture of tissues and organs, and surgical planning have all benefited significantly from the use of three-dimensional (3D) printing during the past few decades. The enthusiasm for customized healthcare has increased because the United States of America launched its Precision Medicine Initiative in 2015. In a nutshell, the phrase “personalized medicine” refers to medical care that is tailored to the patient. Nevertheless, the biomedical materials utilized in 3D printing are often stable and can’t react or be adaptive and intelligent in the body’s interior environment. Ex-situ fabrication of these substances, which includes printing on a flat substrate before releasing it onto the target surface, may cause a discrepancy between the printed portion and the target areas. The 3D printing is one method that might be used to provide customized treatment. The four-dimensional (4D) printing is developed while employing components that can be tweaked with stimulation. Several researchers have been looking at a new area recently that blends medicines with 3D and 4D printing. The development of 4D printing overcomes a number of these issues and creates a promising future for the biomedical industry. Smart materials that have been pre-programmed can be used in 4D printing to create structures that react interactively to outside stimuli. Despite these benefits, dynamic materials created using 4D technology remain in their development. As a result, several ideas for pharmaceutical products and formulas that may be customized and printed have emerged. Furthermore, Spritam®, the first medicine produced by 3D printing, has indeed reached a medical facility. This paper offers a summary of several 3D and 4D printing technologies and how they are used in the pharmaceutical industry for customized medicine and drug delivery systems.

The addition of the time dimension to three-dimensional (3D) printing has introduced four-dimensional (4D) printing technology, which has gained considerable attention in different fields such as medical, art, and engineering. Nowadays, bioscience has introduced some ideas which can be fulfilled by 4D printing. Blending time with variations caused by the situation has many beneficial aspects such as perceptibility and adaptability. Since 4D printing can create a dynamic structure with stimuli-responsive materials, the applications of smart materials, stimulus, and 3D printing are the effective criteria in 4D printing technology. Smart materials with their flexible properties can reshape, recolor, or change function under the effect of the internal or exterior stimuli. Thus, an attractive prospect in the medical field is the integration of the 4D printing approach along with smart materials. This research aims to show the most recent applications of 4D printing technology and smart materials in medical engineering which can show better prospective of 4D printing applications in the future. Also, it describes smart medical implants, tissue engineering, and bioprinting and how they are being used for the 4D printing approach in medical engineering applications. In this regard, a particular emphasis is dedicated to the latest progress in the innovation and development of stimuli-responsive materials that are activated and respond over time to physical, chemical, and biological stimuli and their exploitation through 3D printing methods to fabrication 4D printing smart parts such as intelligent tissue-engineered scaffolds, smart orthopedic implants, and targeted drug delivery systems. On the other hand, major challenges in this technology are explained along with some suggestions for future works to address existing limitations. It is worth noting that despite significant research that has been carried out into 4D printing, it might be more valuable if some investigation is done into 4D bio-printing applications and how this approach will be developed.

Abstract: Additive manufacturing is a highly effective and versatile technology, especially in the medical sector, due to its customization, material complexity, design flexibility, waste minimization, and ability to fabricate intricate shapes that are cumbersome to manufacture by conventional manufacturing techniques. 4D printing plays a significant role in the medical field, especially in the areas not covered by 3D printing technologies, such as smart implants, devices and tools. Also, 4D printing helps doctors to treat more patients with high accuracy and quality. Hence, this manuscript aims to provide an overview of distinct 3D and 4D printing techniques and their emerging applications in the medical sector. A study of 3D printing technologies is presented by explaining the working principles of distinct 3D printing methods: stereo lithography, fusion deposition modeling, inkjet printing, selective laser sintering, selective laser melting and electron beam melting. In addition, the emerging applications of 3D printing in medical sectors (e.g., bioprinting, surgical guides, pharmaceuticals, prostheses, medical devices, dentistry, physiotherapy, etc.), as well as challenges and the future scope of 3D printing, are also discussed. Further, the concept of 4D printing, the market for both 3D and 4D printing, the benefits of 4D printing, the comparison of 3D and 4D printing, limitations, applications, and the future scope of 4D printing in the medical sector are also covered.

3D printing metal implants in orthopedic surgery: Methods, applications and future prospects

Purpose – An increasing amount of attention is being paid to three-dimensional (3D) printing technology. The technology itself is based on diverse technologies such as laser beams and materials. Hence, 3D printing technology is a converging technology that produces 3D objects using a 3D printer. To become technologically competitive, many companies and nations are developing technologies for 3D printing. So to know its technological evolution is meaningful for developing 3D printing in the future. The paper aims to discuss these issues. Design/methodology/approach – To get technological competitiveness of 3D printing, the authors should know the most important and essential technology for 3D printing. An understanding of the technological evolution of 3D printing is needed to forecast its future technologies and build the R & D planning needed for 3D printing. In this paper, the authors propose a methodology to analyze the technological evolution of 3D printing. The authors analyze entire patent documents related to 3D printing to construct a technological evolution model. The authors use the statistical methods such as time series regression, association analysis based on graph theory, and principal component analysis for patent analysis of 3D printing technology. Findings – Using the proposed methodology, the authors show the technological analysis results of 3D printing and predict its future aspects. Though many and diverse technologies are developed and involved in 3D printing, the authors know only a few technologies take lead the technological evolution of 3D printing. In this paper, the authors find this evolution of technology management for 3D printing. Practical implications – If not all, most people would agree that 3D printing technology is one of the leading technologies to improve the quality of life. So, many companies have developed a number of technologies if they were related to 3D printing. But, most of them have not been considered practical. These were not effective research and development for 3D printing technology. In the study, the authors serve a methodology to select the specific technologies for practical used of 3D printing. Originality/value – Diverse predictions for 3D printing technology have been introduced in many academic and industrial fields. Most of them were made by subjective approaches depended on the knowledge and experience of the experts concerning 3D printing technology. So, they could be fluctuated according to the congregated expert groups, and be unstable for efficient R & D planning. To solve this problem, the authors study on more objective approach to predict the future state of 3D printing by analyzing the patent data of the developed results so far achieved. The contribution of this research is to take a new departure for understanding 3D printing technology using objective and quantitative methods.

Additive manufacturing (AM), commonly known as 3D printing, has garnered significant attention across various industries for its flexibility and simplicity in fabrication. This review explores the evolution of AM technologies, encompassing rapid prototyping and 3D printing, which have revolutionized conventional manufacturing processes. The paper discusses the transition from rapid prototyping to AM and highlights its role in creating fully customized products, optimizing topologies, and fabricating complex designs, especially in the aerospace, medical, automotive, defense energy and food industries. The study delves into the fundamental principles of 3D and 4D printing technologies, detailing their processes, materials, and applications. It provides an overview of the various AM techniques, such as Vat photopolymerization, powder bed fusion, material extrusion, and directed energy deposition, shedding light on their classifications and applications. Furthermore, the paper explores the emergence of 4D printing, which introduces an additional dimension of “time” to enable dynamic changes in printed structures. The role of AM in different industries, including aerospace, medical, automotive, energy, and Industry 4.0, is thoroughly examined. The aerospace sector benefits from AM's ability to reduce production costs and lead times, while the medical field leverages bioprinting for synthetic organ fabrication and surgical equipment development. Similarly, AM enhances flexibility and customization in automotive manufacturing, energy production, and Industry 4.0 initiatives Overall, this review provides insights into the growing significance of AM technologies and their transformative impact on various industries. It underscores the potential of 3D and 4D printing to drive innovation, optimize production processes, and meet the evolving demands of modern manufacturing.

Chapter 18 - 3D printing technology in drug delivery

Three-dimensional (3D) printing technology holds great potential to fabricate complex constructs in the field of regenerative medicine. Researchers in the surgical fields have used 3D printing techniques and their associated biomaterials for education, training, consultation, organ transplantation, plastic surgery, surgical planning, dentures, and more. In addition, the universal utilization of 3D printing techniques enables researchers to exploit different types of hardware and software in, for example, the surgical fields. To realize the 3D-printed structures to implant them in the body and tissue regeneration, it is important to understand 3D printing technology and its enabling technologies. This paper concisely reviews 3D printing techniques in terms of hardware, software, and materials with a focus on surgery. In addition, it reviews bioprinting technology and a non-invasive monitoring method using near-infrared (NIR) fluorescence, with special attention to the 3D-bioprinted tissue constructs. NIR fluorescence imaging applied to 3D printing technology can play a significant role in monitoring the therapeutic efficacy of 3D structures for clinical implants. Consequently, these techniques can provide individually customized products and improve the treatment outcome of surgeries.

3D printing technology has a wide range of applications in various industries. It is widely used to produce complex 3D structures, but it has some limitations such as a limited amount of material, etc., which have been overcome with the introduction of 4D printing technology. In 4D printing, which involves time as a function and the combination of smart materials, this enables properties such as changing form and function.[1]Five-dimensional (5D) printing is a new branch of additive manufacturing (AM) with great potential to solve problems in engineering, medicine, dentistry and other related fields. It is the latest technological advancement used to produce complex and intricately shaped products, implants and devices with much better physical properties than those obtained by three-dimensional (3D) printing. The concept of 5D printing originated from William Yerazunis of the American University of Mitsubishi Electric Research Laboratories (MERL). In 5D printing, the printing plate also moves with the printing head during the printing process. in 3D printing techniques.[1]four-dimensional (4D) printing is the concept of using a smart material that can change the shape of a printed object over time as the temperature changes. [2] One of the advantages of 5D printing is the use of 25% less material than 3D printing. Five-dimensional printing is all about efficiently manufacturing this complex and curved structure with maximum strength. Using computer-aided design (CAD) data to produce super strong dental implants, orthodontic brackets, crowns, aligners, bridges and appliances. This CAD data is created using the dentist's 3D scanner / different design software.[1] 5D printing of five axes: [1], 1.X-axis ;2. Y-axis;3. Z axis; 4. Movable print head and 5. Movable printing base.5D printing is an advanced manufacturing technology that builds on the concept of 3D printing and adds customization options and features. While 3D printing requires the creation of three-dimensional objects layer by layer, 5D printing allows additional functions or features to be added to a printable object, often dynamically or responsively. its role in dentistry may be limited due to the newness of the technology.