Additive manufacturing (3D printing) has significantly changed the prototyping process in terms of technology, construction, materials, and their multiphysical properties. Among the most popular 3D printing techniques is vat photopolymerization, in which ultraviolet (UV) light is deployed to form chains between molecules of liquid light-curable resin, crosslink them, and as a result, solidify the resin. In this manuscript, three photopolymerization technologies, namely, stereolithography (SLA), digital light processing (DLP), and continuous digital light processing (CDLP), are reviewed. Additionally, the after-cured mechanical properties of light-curable resin materials are listed, along with a number of case studies showing their applications in practice. The manuscript aims at providing an overview and future trend of the photopolymerization technology to inspire the readers to engage in further research in this field, especially regarding developing new materials and mathematical models for microrods and bionic structures.

Improving the surface roughness quality of 3D printed components, especially metallic ones, which are fabricated from the selective laser melting (SLM) method, has drawn enormous attention from the research community. It should be noted that various studies on this topic have reported that precise surface roughness results can be obtained with various techniques that are indeed not cost-effective. Differing itself from these studies, this manuscript investigates an economical solution for fabricating and surface treating SLM components. Specifically, the inspected specimens were printed with recycled 316L stainless steel powder and treated solely with two abrasive surface finishing methods. In the manuscript, two scanning strategies namely meander and stripes, and three types of surfaces were investigated. Subsequently, their 2D and 3D surface roughness results were elaborated. After the proposed herein abrasive treatment, 3D surface roughness arithmetical mean height of a surface (Sa) value of 0.9 µm can be achieved.

The combination of topology optimization (TO) and 3D printing has revolutionized the way components are designed and fabricated. In view of this, this manuscript presents a TO workflow considering the frame of a scooter. In particular, TO is employed to redesign the scooter frame based on a commercial one. The topologically optimized frame is then fabricated with stainless steel 316L utilizing the selective laser melting (SLM) method. In particular, technical obstacles encountered during the process and according solutions are recorded. Given the herein notes, readers who are working with the two technologies can anticipate the technical problems and deliver more effective solutions should any of them arise.

This article aims to review a redesign approach of a student racing car’s clutch lever component, which was topologically optimized and manufactured by Additive Manufacturing (AM). Finite Element Method (FEM) analysis was conducted before and after a Topology Optimization (TO) process in order to achieve equivalent stiffness and the desired safety factor for the optimized part. The redesigned clutch lever was manufactured by using AM–Selective Laser Melting (SLM) and printed from powdered aluminum alloy AlSi10Mg. The final evaluation of the study deals with the experimental test and comparison of the redesigned clutch lever with the existing part which was used in the previous racing car. Using TO as a main redesign tool and AM brought significant changes to the optimized part, especially the following: reduced mass of the component (10%), increased stiffness, kept safety factor above the 3.0 value and ensured the more aesthetic design and a good surface quality. Moreover, using TO and AM gave the opportunity to consolidate multi-part assembly into a single component manufactured by one manufacturing process that reduced the production time. The experimental results justified the simulation results and proved that even though the applied load was almost 1.5× higher than the assumed one, the maximum von Mises stress on the component was still below the yield limit of 220 MPa.

The integration of the Internet of Things (IoT) in healthcare has been a popular topic in recent years. This article provides a comprehensive review of the medical IoT for healthcare, emphasizing the state of the art, the enabling technologies to adopt virtuality and reality interaction, and human-centered communication for healthcare (the Metaverse, Extended Reality (XR), blockchain, Artificial Intelligence (AI), robotics). In particular, we assess the number of scientific articles and patents within the period 2015–2022. We then use the two-stage process following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and screening techniques. From that, the relations among the published papers can be visualized. This study examines the insights by evaluating the weights and connections of the nodes in the bibliometric networks. The reviewed papers showcase the rapid growth of IoT-related studies and intellectual property developments, reflecting the burgeoning interest and investment in this domain. As this paper delves into the network of interconnections between these works, it fosters a deeper understanding of the current state of IoT applications in healthcare and uncovers potential research gaps and areas for future exploration. This paper also provides a brief view of the role of IoT in healthcare research and application in combination with emerging technologies such as AI, blockchain, the IoT-enabled Metaverse, robotics, and cloud computing. The article can serve as a guideline and inspiration for both researchers and practitioners in the smart health service sector.