In articular joint implants, polymeric inserts are usually exploited for on-contact sliding surfaces to guarantee low friction and wear, a high load-bearing capacity, impact strength and stiffness, and biocompatibility. Surface micro-structuring can drastically reduce friction and wear by promoting hydrostatic friction due to synovial fluid. Ultra-High Molecular Weight Polyethylene (UHMWPE) is a suitable material for these applications due to its strong chemical resistance, excellent resistance to stress, cracking, abrasion, and wear, and self-lubricating property. However, surface micro-texturing of UHMWPE is hardly achievable with the currently available processes. The present study investigates UHMWPE's micro-textured surface replication capability via injection molding, comparing the results with the more easily processable High-Density Polyethylene (HDPE). Four different micro-texture cavities were designed and fabricated on a steel mold by micro-EDM milling, and used for the experimental campaign. Complete samples were fabricated with both materials. Then, the mold and samples were geometrically characterized, considering the dimensions of the features and the texture layout. The replication analysis showed that HDPE samples present geometrical errors that span from 1% to 9% resulting in an average error of 4.3%. In comparison, the UHMWPE samples display a higher variability, although still acceptable, with percentage errors ranging from 2% to 31% and an average error of 11.4%.

Carbon fiber composite materials are intensively used in many manufacturing domains such as aerospace, aviation, marine, automation and civil industries due to their excellent strength, corrosion resistance, and lightweight properties. However, their increased use requires a conscious awareness of their entire life cycle and not only of their manufacturing. Therefore, to reduce waste and increase sustainability, reparation, reuse, or recycling are recommended in case of defects and wear. This can be largely improved with reliable and efficient non-destructive defect detection techniques; those are able to identify damages automatically for quality control inspection, supporting the definition of the best circular economy options. Hyperspectral imaging techniques provide unique features for detecting physical and chemical alterations of any material and, in this study, it is proposed to identify the constitutive material and classify local defects of composite specimens. A Middle Wave Infrared Hyperspectral Imaging (MWIR-HSI) system, able to capture spectral signatures of the specimen surfaces in a range of wavelengths between 2.6757 and 5.5056 µm, has been used. The resulting signatures feed a deep neural network with three convolutional layers that filter the input and isolate data-driven features of high significance. A complete experimental case study is presented to validate the methodology, leading to an average classification accuracy of 93.72%. This opens new potential opportunities to enable sustainable life cycle strategies for carbon fiber composite materials.

In this paper, the manufacturing challenges and related technological solutions concerning the prototyping of microwave ablation (MWA) probes are addressed. In particular, the intertwined aspects pertaining probe design, fabrication and target performance are tackled. The development of a 14G MWA probe prototype, working at a frequency of 2.45 GHz, is proposed as a case study, describing design efforts and the use of rapid prototyping technologies combined with other manufacturing processes. A specific focus is dedicated to the insulating part of the probe radiating section, featuring high aspect ratio and complex shape, which was fabricated by means of Digital Light Processing (DLP) and by using a biocompatible material, the EnvisionTEC E-Shell® 300. Furthermore, the probe handling, properly designed to arrange cables and tubes routing, was fabricated by means of Fused Deposition Modeling (FDM) technology. Finally, ex vivo experiments conducted on bovine liver showed satisfactory treatment performance and structural reliability of the 14G MWA probe prototype. Besides being characterized by a good impedance matching (S11 = -25 dB), prototype performance were also in good agreement with design simulations and even satisfying if compared to other results available in literature as, with an input radiation power of 40 W, the ablated zone after a 10 min treatment exhibited a ratio of the radial and longitudinal axis of 0.66.

- NOTA BENE: la rivista è IET collaborative intelligent manufacturing ISSN 25168398

Traditional 3-degree of freedom micro-EDM milling adopts the layer-by-layer approach to easily compensate for the tool wear and reduce the corresponding machining error. However, the layer-by-layer approach discretizes the nominal geometry and influences machining accuracy. The problem becomes more evident when free-form surfaces are fabricated. Similar to conventional milling, the adoption of interpolating rotational axes can potentially improve the process performance in terms of geometrical accuracy. In the present study, high-precision rotating axes are adopted to investigate the machining strategy when the tool is engaged using a 4th rotating axis in freeform surface finishing. The study is developed by performing micro-milling tests of cylindrical slots, analyzing the tool wear behavior and the process performance, and comparing them to the planar layer-by-layer micro-milling approach. Results show the feasibility of the proposed approach.

Polymeric components in articular joint implants are usually exploited to guarantee low friction and wear, high load bearing capacity, impact strength and stiffness, and biocompatibility. Micro-structuring of on-contact sliding surfaces can drastically reduce the friction and wear by promoting hydrostatic friction due to synovial fluid at the components interface. In these applications, Ultra-High Molecular Weight Polyethylene (UHMWPE) is a suitable material, but its current manufacturing process hinders surface micro-texturing. In the present study, the microtexturing surface replication capability of Ultra-High Molecular Weight Polyethylene via injection moulding is investigated considering four different micro-textures fabricated on a steel mould by micro-EDM milling. The results show that the injection molding allows to obtain a good replication capability.

Hybrid polymer composites are very promising for applications in a wide variety of sectors, such as automotive, aerospace, robotics, energy and construction. These materials consist of a polymer matrix and two or more fillers, which synergically interact resulting in enhanced specific properties and performance. Among hybrid polymer composites, those based on carbon fibers reinforced poly(ether ether ketone) (C-PEEK) are gaining a primary role for their excellent mechanical and chemical properties; zirconium oxide (ZrO2) nanoparticles can further enhance these properties, improving also the wear resistance. In this paper, a new hybrid C-PEEK+ZrO2 composite has been studied and its mechanical properties compared with its reference composite C-PEEK.

The effects of micro texturing on several surface characteristics, i.e. biofouling, wetting, lubrication, cell adhesion, have been widely investigated. In the healthcare sector, and specifically medical devices, micro-structured surfaces are exploited to improve tribological properties or foster the osseointegration of surgical implants. Polymeric components in joint implants substitute cartilages of natural joints guaranteeing biocompatibility, low friction and wear, high load bearing capacity, impact strength and stiffness. Among these, tribological properties are very important for their direct impact on the implant lifespan. Micro-structuring of on-contact sliding surfaces can drastically reduce the friction and wear by promoting hydrostatic friction due to synovial fluid at the components interface. In these applications, Ultra-High Molecular Weight Polyethylene (UHMWPE) is a successful material but its current manufacturing process hinders surface micro-texturing. In this scenario, a production process chain, combining micro-injection molding of UHMWPE with molds made by Stereolithography (SLA) can be a successful option for investigating several micro-structuring designs reducing time and cost for the analysis. In this work, the micro-texturing surface manufacturing capability of an SLA technology is investigated through four micro-textures, two mold materials, three orientations in 3Dprinting and two micro-features heights. Micro-texturing patterns are realized and characterized on the molds. The same molds are then used for injection molding of parts, studying the process parameters and the replication capability on molded samples. The results show that dimension of the micro-textures brings the SLA to its limit, with good agreement on pin height and an error on the pin diameter between 24 and 108?m. The 3Dprinting orientation can improve both pin shape and surface roughness. The injection molding experimentation allows to obtain a good replication capability.

Flexible electronics is one of the most promising trends in the electronics industry, with increasing implementations in several application fields. However, in industrial applications, the assembly of film-based coverlays is still performed manually, representing a bottleneck in the whole production cycle, a source of defects caused by human errors, and introducing fatiguing tasks, such as the removal of the protective film covering the base material. In a novel methodology, this latter challenge is achieved by relying on the mechanical action of a rotating tool impacting the protective film. Such a process is typically stochastic and dependent on several parameters related to the tool-coverlay interaction, and the flexibility of film-type introduces further complexity. The aim of this paper is to investigate the influence of working conditions on the reliability of the process (i.e., success rate of the removal of the protective film). Finite element method (FEM) simulations are used to investigate and assess the stiffness exhibited by the component in response to the impacting force; therefore, a favorable gripping configuration is identified. An experimental campaign of the automated process is presented, aimed at assessing the effects of process parameters (tool rotating speed, adhesive thickness, approaching speed) on the protective film detachment. The results show that the process is predominantly affected by component-specific parameters, which, in turn, are significantly dependent on material supply conditions. Finally, useful insights are drawn to optimize the process and improve the design of the gripper of the robotized workcell.

Quality evaluation of micro injection molded products is a complex task, in particular when instruments basing on contact methods are used and issues in measurements could arise due to the contact tool dimension not fitting well with extremely narrow features. Therefore, in these cases, optical methods may be preferred for the evaluation of molded products' dimensions and surface quality, especially for parts devoted to applications requiring functional purposes. In this context, the present paper proposes the use of surface parameters as a quality index for the evaluation of both the micro injection molding process and the resulting products. To this aim, two experimental procedures were implemented to allow for: (i) the evaluation of the most suitable surface parameters identified in relation to the process parameters; (ii) comparisons of the surface parameters findings with those obtained by classic dimensional quantity via a designed experimental plan (DoE). The results show that the surface parameters, evaluated in critical areas of the components, can ensure reliable estimates for the surface quality of the molded parts and can be preferred in comparison to linear measurements.

This document gives guidelines for a uniform framework, transversal with respect to the different robot categories and limited to those robots and robotic applications characterized by human-robot collaboration, for the development and/or use of testing procedures, applicable to different robot categories and use scenarios. This document is informative and is not aimed at substituting or simplifying verification and/or validation procedures required by standards. The objectives of this document are the following: -- define an approach for the development and use of procedures for testing safety in human-robot collaboration at a system level, based on safety-relevant human-robot collaboration skills and limited to the mechanical hazards; -- define a comprehensive list of application-driven, technology-invariant safety-relevant human-robot collaboration skills valid across different domains; -- provide a template for system-level validation protocols; -- by way of example, present two system-level validation protocols, applicable to multiple domains.

Due to rapid changes in consumer demand and electronic technology advancements, electronics products in general, and specifically home automation segment products, are becoming obsolete at a very high rate. Therefore, strategies for End-of-Life (EOL) management need to be adapted. However, EOL management of these products is not globally approached due to the lack of autonomous, integrated, modular, and flexible systems to cope with the wide variety, and heterogeneous complicate structure of products. This paper reviews current practices and issues related to EOL management of printed circuit boards (PCBs) and mechatronics products in the home automation segment, focusing on their different material compositions as well as on the uses of these raw materials in the circular economy perspective. In addition, this paper provides possible Cyber-Physical System (CPS) implementation scenarios using physical tools available at the STIIMA-CNR de-manufacturing pilot plant. Eventually, this paper highlights challenges and guidelines to develop a new generation of advanced EOL management through the Cyber-Physical System technique.

Drop on demand (DoD) inkjet printing is a high precision, non-contact, and maskless additive manufacturing technique employed in producing high-precision micrometer-scaled geometries allowing free design manufacturing for flexible devices and printed electronics. A lot of studies exist regarding the ink droplet delivery from the nozzle to the substrate and the jet fluid dynamics, but the literature lacks systematic approaches dealing with the relationship between process parameters and geometrical outcome. This study investigates the influence of the main printing parameters (namely, the spacing between subsequent drops deposited on the substrate, the printing speed, and the nozzle temperature) on the accuracy of a representative geometry consisting of two interdigitated comb-shape electrodes. The study objective was achieved thanks to a proper experimental campaign developed according to Design of Experiments (DoE) methodology. The printing process performance was evaluated by suitable geometrical quantities extracted from the acquired images of the printed samples using a MATLAB algorithm. A drop spacing of 140 µm and 170 µm on the two main directions of the printing plane, with a nozzle temperature of 35 °C, resulted as the most appropriate parameter combination for printing the target geometry. No significant influence of the printing speed on the process outcomes was found, thus choosing the highest speed value within the investigated range can increase productivity.

Cyber-Physical Production Systems (CPPS) are promised to be the systems that will drive technical transformation in manufacturing in the context of Industry 4.0. However, the role of human operators is still decisive due to the intrinsic human flexibility to analyze, learn and face unpredicted circumstances, forcing to an approach based on fully collaborative environments between humans and machines. However, a validated and repeatable method to evaluate and monitor these interactions and the general performance metrics of the system is still missing. This paper introduces a new holistic method based on a model to set indices and metrics to assess the performance-based interactions while considering the collaborative nature of the actions under different dimensions: i) operator and user experience aspects, ii) machine specific indicators, iii) human-machine collaboration, and iv) production indicators. Finally, a collaborative industrial case is exposed to exemplify the use of the proposed method.

Collaborative robots (cobots) are increasingly finding use beyond the traditional domain of manufacturing, in areas such as healthcare, rehabilitation, agriculture and logistics. This development greatly increases the size and variations in the level of expertise of cobot stakeholders. This becomes particularly critical considering the role of human safety for collaborative robotics applications. In order to support the wide range of cobot stakeholders, the EU-funded project COVR "Being safe around collaborative and versatile robots in shared spaces" has developed a freely available, web-based Toolkit that offers support to understand how to consider the safety of cobot applications. This paper describes the state of the art for ensuring safety across various life cycle phases in the development and implementation of collaborative robotics applications and highlights how the Toolkit provides practical support during these tasks. The Toolkit aims to be the most comprehensive resource for supporting cobot stakeholders in ensuring the safety of their applications.

Despite the widespread use of electronic devices and consumer products integrating flexible electronics, in industrial practice, the assembly process of film-based coverlays is still performed manually, and this, in turn, affects process accuracy in first place. Additionally, the related manual tasks can be troublesome for workers, causing stress and fatigue. As a result, such a process can represent a bottleneck in the fabrication of Flexible Printed Circuit Boards (FPCBs). In the present paper, the architecture of a gripper is proposed as the core device of a completely automated film-coverlay assembly process. The architecture of the gripper is vacuum-based and exploits the action of several independent valves, enabling the grip configuration according to the geometry of the component. The gripper operation is shown by implementing specific solutions related to the removal of the coverlay protective film and partial coverlay thermal bonding, thus providing also a detailed description of the phases concerning a feasible automated assembly process. The results of the tests concerning the evaluation of both solutions are reported and discussed in the paper. Finally, a simplified gripper version is prototyped to perform some of the tests, and it is also used to preliminarily assess the performance of the gripping strategy, with good results.

In this work, the moldability via micro-injection molding (?IM) of nano-filled polyamide 6 (PA6) based systems and the microstructural characteristics of the micro-injected parts were investigated and compared to those observed via traditional injection molding (IM). Two types of nano-fillers, different in nature and geometry, were examined, namely carbon nanotubes and silicate layers. The presence of nano-fillers did not impair the mold replication capability of PA6 in the ?IM process. A micro-rib and a standard dumbbell specimen for tensile tests were used as reference micro- and macro-injected part, respectively. Transmission Electron Microscopy, Wide and Small Angle X-ray Scattering and Differential Scanning Calorimetry analyses showed that, due to the different thermomechanical histories during ?IM and IM, the micro- and the macro-parts have different microstructures, influenced also by the filler type. Both nano-filler dispersion and PA6 crystallinity were influenced.

Drop on demand (DoD) inkjet printing is a high precision, non-contact and maskless additive manufacturing technique employed in producing high precision micrometer-scaled geometries allowing a free design manufacturing for flexible devices and printed electronics. This study investigates the influence of the main printing parameters (namely, the spacing between subsequent drops deposited on the substrate, the printing speed, and the nozzle temperature) on the dimensional accuracy of a representative geometry consisting of two interlocked comb shapes. The study objective was achieved thanks to a proper experimental campaign, which was developed according to Design of Experiments (DoE).

Printed circuit boards (PCBs) are made of several materials, including platinum, gold, silver, and rare earth elements, which are very valuable from a circular economy perspective. The PCB end of life management starts with the component removal, then the PCBs are shredded into small particles. Eventually, different separation methods are applied to the pulverized material to separate metals and non-metals. The corona electrostatic separation is one of the methods that can be used for this purpose since it is able to separate the conductive and non-conductive materials. However, the lack of knowledge to set the process parameters may affect the efficiency of the corona electrostatic separation process, ultimately resulting in the loss of valuable materials. The simulation of particle trajectory can be very helpful to identify the effective process parameters of the separation process. Thus, in this study, a simulation model to predict the particles trajectories in a belt type corona electrostatic separator is developed with the help of COMSOL Multiphysics and MATLAB software. The model simulates the particle behavior taking into account the electrostatic, gravitational, centrifugal, electric image, and air drag forces. Moreover, the predicted particles trajectories are used to analyze the effects of the roll electrode voltage, angular velocity of roll electrode, and size of the particles on the separation process.