Purpose The purpose of this study is to explore a methodology for connecting microelectromechanical system sensors - i.e. inertial measurement unit (IMU) - to an Arduino-based microcontroller, using graphene-based conductive filament and flexible thermoplastic polyurethane (FTPU) filament and low-cost dual material extrusion technology. Design/methodology/approach A series of electrical tests were carried out to determine the maximum resistance the conductive paths may take to connect printed circuit boards (PCB). To select the most suitable printing material, three types of conductive filaments were examined. Then an experiment was carried out to find the best printing parameters in terms of printing speed, printing temperature and layer height to minimise resistivity. The size of the conductive path was also analysed. A final prototype was designed and printed according to optimised printing settings and maximum allowable resistances for each line and considering different geometries and printing strategies to reduce cross-contamination among paths. Findings For the Black Magic 3D conductive filament, the printing speed and layer height played a significant role regarding resistivity, while the printing temperature was not very important. The infill pattern of the conductive paths had to be aligned with the expected current path, while using air gaps between two adjacent paths resulted in the best approach to reducing cross-contamination. Moreover, the cross-section size of

This paper presents a user-centered methodology to co-design and co-evaluate wearables that has been developed following a research-through design methodology. It has been based on the principles of human-computer interaction and on an empirical case entitled "Design and Development of a Low-Cost Wearable Glove to Track Forces Exerted by Workers in Car Assembly Lines" published in Sensors. Insights from both studies have been used to develop the wearable co-design domino presented in this study. The methodology consists of different design stages composed of an ideation stage, digital service development and test stages, hardware development and test stage, and a final test stage. The main conclusions state that it is necessary to maintain a close relationship between human factors and technical factors when designing wearable. Additionally, through the several studies, it has been concluded that there is need of different field experts that should co-design and co-evaluate wearable iteratively and involving users from the beginning of the process.

Wearable electronics make it possible to monitor human activity and behavior. Most of these devices have not taken into account human factors and they have instead focused on technological issues. This fact could not only affect human¿computer interaction and user experience but also the devices¿ use cycle. Firstly, this paper presents a classification of wearable design requirements that have been carried out by combining a quantitative and a qualitative methodology. Secondly, we present some evaluation procedures based on design methodologies and human¿computer interaction measurement tools. Thus, this contribution aims to provide a roadmap for wearable designers and researchers in order to help them to find more efficient processes by providing a classification of the design requirements and evaluation tools. These resources represent time and resource-saving contributions. Therefore designers and researchers do not have to review the literature. It will no be necessary to carry out exploratory studies for the purposes of identifying requirements or evaluation tools either.

Additive Manufacturing devices or 3D printers allow the possibility of creating almost anything. One of the most promising fields of application are wearable devices, which can be directly printed on textiles. This paper aims to study adhesion forces and warping effects when depositing a polymer onto a textile with a low-cost extrusion 3D printer. To achieve this, two different polymers (PLA and Filaflex) and six of the most common textile materials were selected. L-shaped specimens were printed by combining the two polymers and the six textiles. Most of the common printing settings were fixed for both materials, while the layer quality was 0.1 mm and 0.2 mm. Once printed, they were inspected with a Coordinate Measuring Machine and the deformation of each specimen was quantified by calculating their maximum and minimum displacements. Afterwards, each specimen was axially tested to evaluate the adhesion forces between the polymer and the textile. In terms of warping, flexible filament showed the lowest values independent of printing quality (0.56 mm and 0.3 mm) relative to the rigid filament (0.73 mm and 0.8 mm). In terms of adhesion, the combination of a porous textile and a flexible filament got the highest values, regardless of the layer height selected. The conclusion of this study is that polymer textile deposition can be a real manufacturing strategy that should be considered when thinking about the design of a wearable device to be worn on the body.

Wearables are gaining widespread use and technologies are making it possible to monitor human physical activity and behaviour as part of connected infrastructures. Many companies see wearables as an opportunity to enhance worker safety since they can monitor their workers' activity in real life scenarios. One of the goals of this technology is to integrate existing electronic components, such as sensors or conductors, in order to create fully wearable systems. This integration is constrained not only by technical factors but also by user requirements and internal company standards. This paper considers such constraints and presents preliminary research for the design of a wearable glove as a new tool to track forces exerted by workers in car assembly lines. The objective of the glove is to measure forces and compare these to maximum forces already identified by the company. Thus, the main objectives are to: (1) integrate the components based on the requirements of the users and the context of application, and (2) provide a new tool that can be used in situ to track workers. This study was carried out in close collaboration with Volkswagen through a human-centred iterative design process. Thus, this paper presents the development of a wearable device glove based on a specific design methodology where both the human and technological aspects are considered.

Shin pads are part of the mandatory equipment footballers must wear so as to prevent lesions. Most players wear commercially available shin pads made from a variety of common materials (polypropylene or polyethylene) and high-resistance materials (glass fibre, carbon fibre or Kevlar) using traditional manufacturing techniques. Additive manufacturing was used years ago to deliver customised rigid shin pads, but they did not offer any significant advantage in terms of materials or design compared to traditional shin pads. This project analyses a novel approach to the design and manufacture of shin pads for football players that combines existing digitisation tools, lattice structures and a multi-material additive manufacturing device. A total of 24 different additive manufacturing geometries were evaluated using a customised rig where a 1-kg impactor was released from several heights (100-400 mm). The impact acceleration, the transmitted force to the leg and penetration were calculated. Results were compared against two commercially available shin pads. Results show that two of the additive manufacturing specimens tested at the highest drop height had lower impact accelerations than commercial shin pads. They had an acceleration reduction between 42% and 68% with respect to the commercial shin pads. Regarding the penetration, the improvement achieved with additive manufacturing specimens ranged from 13% to 32%, while the attenuation and the contact times were similar.

An Abdominal Aortic Aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta at least 1.5 times its normal diameter. The criterion of maximum diameter is still used in clinical practice, although numerical studies have demonstrated the importance of biomechanical factors for rupture risk assessment. AAA phantoms could be used for experimental validation of the numerical studies and for pre intervention testing of endovascular grafts. We have applied multi-material 3D printing technology to manufacture idealized AAA phantoms with anisotropic mechanical behavior. Different composites were fabricated and the phantom specimens were characterized by biaxial tensile tests while using a constitutive model to fit the experimental data. One composite was chosen to manufacture the phantom based on having the same mechanical properties as those reported in the literature for human AAA tissue; the strain energy and anisotropic index were compared to make this choice. The materials for the matrix and fibers of the selected composite are, respectively, the digital materials FLX9940 and FLX9960 developed by Stratasys. The fiber proportion for the composite is equal to 0.15. The differences between the composite behavior and the AAA tissue are small, with a small difference in the strain energy (0.4%) and a maximum difference of 12.4% in the peak Green strain ratio. This work represents a step forward in the application of 3D printing technology for the manufacturing of AAA phantoms with anisotropic mechanical behavior. (C) 2017 Elsevier Ltd. All rights reserved.

An abdominal aortic aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta of at least 1.5 times its normal diameter. Although the criterion of maximum diameter is still used in clinical practice to decide on a timely intervention, numerical studies have demonstrated the importance of other geometric factors. However, the major drawback of numerical studies is that they must be validated experimentally before clinical implementation. This work presents a new methodology to verify wall stress predicted from the numerical studies against the experimental testing. To this end, four AAA phantoms were manufactured using vacuum casting. The geometry of each phantom was subject to microcomputed tomography (lCT) scanning at zero and three other intraluminal pressures: 80, 100, and 120 mm Hg. A zero-pressure geometry algorithm was used to calculate the wall stress in the phantom, while the numerical wall stress was calculated with a finite-element analysis (FEA) solver based on the actual zero-pressure geometry subjected to 80, 100, and 120 mm Hg intraluminal pressure loading. Results demonstrate the moderate accuracy of this methodology with small relative differences in the average wall stress (1.14%). Additionally, the contribution of geometric factors to the wall stress distribution was statistically analyzed for the four phantoms. The results showed a significant correlation between wall thickness and mean curvature (MC) with wall stress.

Rheumatoid arthritis is a chronic disease affecting the joints. Treatment can include immobilisation of the affected joint with a custom-fitting splint, which is typically fabricated by hand from low temperature thermoplastic, but the approach poses several limitations. This study focused on the evaluation, by finite element analysis, of additive manufacturing techniques for wrist splints in order to improve upon the typical splinting approach. An additive manufactured/3D printed splint, specifically designed to be built using Objet Connex multi-material technology and a virtual model of a typical splint, digitised from a real patient-specific splint using three-dimensional scanning, were modelled in computer-aided design software. Forty finite element analysis simulations were performed in flexion-extension and radial-ulnar wrist movements to compare the displacements and the stresses. Simulations have shown that for low severity loads, the additive manufacturing splint has 25%, 76% and 27% less displacement in the main loading direction than the typical splint in flexion, extension and radial, respectively, while ulnar values were 75% lower in the traditional splint. For higher severity loads, the flexion and extension movements resulted in deflections that were 24% and 60%, respectively, lower in the additive manufacturing splint. However, for higher severity loading, the radial defection values were very similar in both splints and ulnar movement deflection was higher in the additive manufacturing splint. A physical prototype of the additive manufacturing splint was also manufactured and was tested under normal conditions to validate the finite element analysis data. Results from static tests showed maximum displacements of 3.46, 0.97, 3.53 and 2.51mm flexion, extension, radial and ulnar directions, respectively. According to these results, the present research argues that from a technical point of view, the additive manufacturing splint design stands at the same or even better level of performance in displacements and stress values in comparison to the typical low temperature thermoplastic approach and is therefore a feasible approach to splint design and manufacture.

The book focuses on four exemplified EM&Ts areas as results of the methods, gaps and issues related to their teaching methods. The four areas are: Experimental Wood-Based EM&Ts, Interactive Connected Smart (ICS) Materials Wearable-based, Carbon-based & Nanotech EM&Ts and Advanced Growing. It provides the setting up of a common/ novel method to teaching EM&Ts: to create new professional in young students, and to develop new guidelines and approach.

The increasing relevance of occupational injuries and illness related to lean manufacturing strategies in automotive assembly lines brings an increasing interest in this industry by the research and development of new tools and methods for the evaluation and prevention of work-related musculoskeletal disorders (WMSDs). However, few studies have focused on assessing the exposures to the hand region whereas disorder in this region remain at the primary tier of the prevalence ranking. Herein, this paper presents a low-cost, wearable inertial measurement unit (IMU) to measure workplace demands. This technology was selected after analysing an assessment scale composed of seven of the common ergonomic assessment tools and methods. After a brief verification through a laboratory goniometry experiment, eleven joint angles of a volunteer¿s hand were measured. The results indicated that the mean difference between the values measured by participants and the values obtained directly from the wearable is 2.44°, which has the same accuracy level of the commercial products. The proposed device is scalable enough to be iterated by further improvements, including conductive fabric 3D printing technology.