Polylactic acid (PLA) is one of the most extensively used biodegradable aliphatic polyester produced from renewable resources, such as corn starch. Due to its qualities, PLA is a leading biomaterial for numerous applications in medicine as well as in industry, replacing conventional petrochemical - based polymers. The purpose of this paper is to highlight the mechanical properties, such as tensile stress, of pure PLA specimens in comparison with PLA based-composites, with three different added materials in PLA mass: Copper, Aluminum and Graphene, as well as the influence of filament angle deposition on these properties. In order to check if the the filling density of the specimen influences the ultimate tensile stress (UTS), three different filling percentages (60%, 80% and 100%) have been chosen in the experimental tests. In this context, the mechanical characteristics of four different filament types based on PLA material, starting from pure PLA to PLA with Aluminum, Copper or Graphene filler are compared. Understanding and controlling these parameters is essential for the successful use of PLA and PLA-based composites in different areas such as medical applications, sport equipments and light industry.These tests have been performed due to the fact there is a lack of information concerning the mechanical properties. In the scientific literature, such information is only available for expensive printing systems; for open source printers (as those used in these tests), the information is poor and for some new materials, even inexistant. According to the technical specifications, for an expensive printer the cost may exceed 3000 Euros, with a minimum layer resolution of 100 m, this type of printer can reliably reproduce many 3D objects accurately, in quiter conditions.

Assistive technology plays an important role in rehabilitation. Body-powered tools rely on manual movement of the artificial limb while externally powered machines use actuators to induce mobility and return function. Alternatively, some devices incorporate both systems. In the case of below-the-wrist amputation, availability of such prosthetics is quite limited according to the literature. Our aim was to establish an alternative design for a partial hand prosthetic with both body and external power. A mixed actuation system was conceived. To generate the grasping force required to impel the transitional partial hand prosthetic, three DC motors were used. As a result, a grasping force of 2.8 kgf was possible to achieve at a 600 mA drawn current at 6 V. Furthermore, a locking system and a pretension system were included to enhance device handling. The resulting device came at a calculated cost of 260 euros. The proposed design provides a solution for patients with below the wrist partial hand amputation.

A very important issue that needs to be solved as simply and correctly as possible is how to establish the thermal performance of phase-changing materials (PCM). The undertaken researches have analyzed the values of the thermal performances of the PCM taking into account the method of finite elements and the experimental research, respectively, based on a modern measurement system that was designed and implemented. Butyl stearate which has been encapsulated through complex coacervation in polymethyl methacrylate has been used as a PCM. Samples were made containing 10%, 20%, 30% and 40% PCM, respectively, within their structure. The research has established that at both the hot plate and the cold plate interface, the evolution of the temperature over time, established by both the finite element method (FEM) and experimental research, are quite close, and the best results have been obtained for the P30 sample. A very important thing observed during the finite element method (FEM) is that the simulated thermal flow variation extends between 2700-3110W/m² being small enough not to influence the temperature measurement at the interface of hot or cold plates. Thus, the use of the FEM or the experimental research method can be applied with good results, provided that the correct initial conditions are used in the finite element method and that the experimental research is performed using the best possible apparatus.

Over the years, patients with partial hand loss have relied on expensive prosthetics to recover some of the hand functionality. Fortunately, advancements in additive manufacturing desktop solutions allow transitional prosthetics prices to decrease. Therefore, the present work focused on providing a basic overview of the field and available low-cost 3D-printed upper-limb prosthetic devices. The aim was to develop a basic frame of reference on the field of transitional partial hand prosthetics. Concomitantly, this study also highlights additive manufacturing techniques on which further research can be done whilst helping to provide a new variant for an upper limb prosthetic device. The initial stages, current practices, and future possibilities were considered. Researchers and industry can utilize these findings to develop additional variants for the benefit of patients suffering from partial hand loss.

In this study, an analysis of the behavior of the vertebra during the use of KP and SJ was carried out to understand the kinematics of the movement of the fragments of the vertebra during action and the forces generated in the use of the two methods. For this analysis, the results published by various authors were used. Only the principle of the mechanical actuation of the vertebra fragments was analyzed, without addressing other aspects such as the method of cement introduction, the type of cement used, PMMA hardening times, the duration of the operation, the patient’s recovery time, etc. In addition to the analysis, the authors propose a device that eliminates the inconveniences observed in the two analyzed devices and promises to significantly improve the restoration of the vertebra’s height and, consequently, the patient’s symptoms. The observations show that the type of mechanism articulated at one end has both robustness and greater efficiency in this type of actuation. It is further shown that from this category, the mechanism with two arms (Two-Arm Device) proposed by the authors is superior to the existing ones in terms of robustness and efficiency. The perspectives of TAD are represented by the improvement of the vertebral statics and, consequently, the symptoms of the patients.

Child interviewing in sensitive judicial procedures requires environments and systems that accommodate communication (COM), ergonomic (ERG), sensory/environmental (SEN), safety/privacy (SPR), and functional needs. However, child-sensitive recommendations are not always formulated as engineering specifications directly applicable to product and system development. This study proposes the Adaptive Child Interviewing System Framework (ACISF), a structured approach for translating multidisciplinary evidence into engineering requirements for adaptive child-centred interviewing systems. Child needs (CNs) are systematically translated into functional requirements (FRs), design requirements (DRs), and engineering parameters (EPs), with the resulting relationships consolidated within a Child Need–Engineering Requirement Matrix (CNERM). Adaptability is structured through common (C), age-adaptive (AA), and individually configurable (IC) requirements. The 6–10- and 10–14-year groups provide initial configuration bands, while individual configurability accommodates variation beyond age alone. The framework integrates requirements across five design domains and is demonstrated through the conceptual development of an adaptive child-interviewing cabin addressing spatial, anthropometric, accessibility, environmental, privacy, and safety considerations. The ACISF provides a traceable requirements-engineering architecture connecting child-centred evidence with implementable design solutions and supporting subsequent technical specification, prototype development, expert assessment, usability evaluation, and empirical validation.