Additive manufacturing (AM) or 3D printing is a digital manufacturing process and offers virtually limitless opportunities to develop structures/objects by tailoring material composition, processing conditions, and geometry technically at every point in an object. In this review, we present three different early adopted, however, widely used, polymer-based 3D printing processes; fused deposition modelling (FDM), selective laser sintering (SLS), and stereolithography (SLA) to create polymeric parts. The main aim of this review is to offer a comparative overview by correlating polymer material-process-properties for three different 3D printing techniques. Moreover, the advanced material-process requirements towards 4D printing via these print methods taking an example of magneto-active polymers is covered. Overall, this review highlights different aspects of these printing methods and serves as a guide to select a suitable print material and 3D print technique for the targeted polymeric material-based applications and also discusses the implementation practices towards 4D printing of polymer-based systems with a current state-of-the-art approach.

This research deals with the design and analysis of the nozzle and bed materials required for fluidized bed boiler. The design parameters (Diameter of the bed particle, Range of the terminal velocities, Minimum Fluidization /Bubbling velocities, Maximum amplitude and steady velocities) were calculated using Microsoft Excel by interpreting and solving various formulas. Best bed material was selected on the basis of their various characteristics like porosity, adhesive or cohesive properties, resistance to flow etc. An important characteristic change of air distributor velocity with combustion chamber temperature has been established. ANSYS was used as a simulation tool for the analysis. Static Structural solver was used to carry out the strength analysis of the designed wind box. Likewise, computational fluid dynamics (CFD) was carried out using FLUENT solver. Air flow inside the wind box and fluidization phenomena was verified using FLUENT. Furthermore, the designed system was checked for its validity by comparing the results from the Excel sheets and theoretical calculations with simulation results. Lastly, correlation between temperature and velocity inside combustion temperature were determined to identify their relationship with each other.

Introduction: Pediatric prosthetic knee joints must be appropriately scaled from adult designs to ensure proper gait biomechanics. However, direct dimensional scaling without considering the biomechanical implications may lead to functional discrepancies. This study aimed to evaluate whether using a linear scaling factor can effectively adapt a knee for pediatric use. The study assessed whether such an approach yields a viable pediatric prosthetic knee joint by applying a fixed scaling factor and analyzing the resultant knee geometry. Methods: The linear scaling factor was determined based on the pylon tube diameter, a key constraint in compact pediatric knee design. Given a pediatric pylon diameter of 22 mm, the length of the tibial link was set to 22 mm, yielding a scaling factor of 0.6875 when compared to the adult-sized knee. This scaling factor was used to determine the dimensions of the pediatric four-bar (scaled) knee joint. Static geometric analysis was conducted using GeoGebra^® to model the lower-body segment lengths. The knee joint’s performance was evaluated based on stance and swing phase parameters. These metrics were compared between the scaled knee and a commercial pediatric knee. Results: The geometric analysis revealed that while using the linear scaling factor maintained proportional relationships, certain biomechanical parameters deviated from the expected pediatric norms. The scaled knee achieved a toe clearance of 13.5 mm compared to 19.7 mm in the commercial design and demonstrated a swing-phase heel clearance of 11.6 mm versus 13.3 mm, maintaining negative x/y ratios at heel contact and showing significant stability in push-off moments, while the stance flexion angle remained within an acceptable range. The heel contact and push-off ratios (x/y) were found to be comparable, with the scaled model achieving values of −1.21 and −0.59, respectively. The stance flexion angle measured 10.6°, closely aligning with the commercial reference. Conclusions: Using a linear scaling factor provides a straightforward method for adapting adult prosthetic knee designs to pediatric use. However, deviations in key biomechanical parameters indicate that further experimental study may be required to validate the applicability of the scaled knee joint for pediatric users. Future work should explore dynamic simulations and experimental validations to refine the design further and ensure optimal gait performance.

There is a practical demand to maximise existing data to understand and meet the assistive technology (AT) needs in dynamic populations. Harmonisation can generate new insight by integrating multiple datasets that were not previously comparable into a single longitudinal dataset. We harmonised AT assessment data from three population-based surveys collected several years apart in Nepal: the Living Conditions of Persons with Disabilities (2014-2015), the Multiple Indicator Cluster Survey (2019), and the rapid Assistive Technology Assessment (2022). The harmonised dataset demonstrates a method that can be used for unifying AT surveys in other settings and conducting trend analyses that are necessary for monitoring a population's dynamic AT needs. We set out to explore AT data's potential for harmonisation, and learned there is indeed value in this approach for situating disparate datasets, though the methodology proposed will need further validation.

In low-resource settings such as Nepal, patients with partial hand amputation face serious difficulties in obtaining prosthetic options both in terms of functionality and social acceptability. This paper presents the design of a customized 3D-printed cosmetic prosthesis through local innovation ecosystems to bridge these gaps. With a participatory, user-led process, the project combined the expertise of occupational therapists (OTs), prosthetists and orthotists (P&Os), and engineers to design, produce, and test by iterative cycles a prosthetic device tailored to the anatomical and psychosocial needs of a partial hand amputee. Occupational therapists played a key role in establishing user requirements, that the prosthesis supported legitimate everyday activities, whereas P&Os contributed clinical input on biomechanical alignment and prosthetic performance. Advanced techniques, including computer-aided design and 3D scanning, directed the evolution of anatomically correct prototypes manufactured from thermoplastic polyurethane (TPU), selected for its blend of flexibility and strength. Multiple iterations emphasized aesthetic realism, ergonomic fit, and task-specific function, based on quantitative biomechanical assessment and qualitative user scores. The resulting prototype demonstrated meaningful improvements in user-reported confidence and performance in daily activities, as well as enhanced social integration. Material sustainability, scalability in production, and the technical limits of 3D printing were critically interrogated, highlighting the imperative for context-matched innovation. The study recognizes the capability of locally situated, inter-disciplinary interventions to democratize access to assistive technology in low-resource settings as a replicable model for inclusive healthcare innovation.