The selection for the fabrication of transtibial prosthesis in developing countries is favoring what materials can be readily available. Given numerous options, a multi-criteria decision-making process can be effectively implemented to choose the optimal materials based on design requirement without compromising the target mechanical properties and comfort for the patient. In this study, analytic hierarchy process (AHP), technique for order preference by similarity to ideal solution (TOPSIS) and preference ranking organization method for enrichment evaluations (PROMETHEE) methods were used as a decision-making tool for materials selection of prosthetic socket and pylon tube. The criteria for the candidate materials such as flexural strength, tensile strength, modulus of elasticity, yield strength and impact strength were evaluated and each criterion was given a weight using AHP, while the materials selection calculation was done using TOPSIS and PROMETHEE. For the prosthetic socket, same ranking was observed for both TOPSIS and PROMETHEE. The carbon fiber reinforced composite (CFRC) was ranked first and closely followed by pineapple fiber reinforced composite (PFRC). TOPSIS ranked PFRC highest for the pylon tube material, followed by titanium alloy while this ranking was interchanged in PROMETHEE, putting first preference for the use of pineapple fiber reinforced composite then followed by titanium alloy. Therefore, the pineapple fiber reinforced composite can be an ideal alternative for the standard carbon fiber socket and titanium pylon tubes in fabricating a transtibial prosthesis.

With the growing demand for reliable, low-impact deployment systems in small satellite missions, this work introduces an antenna deployment mechanism using fiber-reinforced shape memory polymer composites (SMPC). The mechanism utilized thermally activated SMPCs for stowage and release, configured with different glass transition temperatures (T_g), tuned through the addition of poly(ethylene glycol) (PEG-600), for sequential actuation. The deployment mechanism consisted of three SMPC components with varying PEG concentrations: SMPC-P (0 wt%), SMPC-5 (5 wt%), and SMPC-10 (10 wt%). For component design, three bending angle configurations (BAC) of 20°, 30°, and 40° were tested. The samples exhibited the highest fixity ratio (93.58%, 95.76%, and 96.52% for SMPC-P, SMPC-5, and SMPC-10, respectively) when conformed to the 20° BAC. All samples achieved full recovery within 2 min, with PEG-incorporated composites exhibiting more uniform behavior across cycles, while recovery rates varied by material and BAC. Deployment testing confirmed the antenna was released successfully across all BACs. The 20° BAC exhibited the fastest response, completing deployment 24 s and 30 s ahead of the 30° and 40° BACs, respectively. The proposed mechanism exhibits promising potential for integration in future CubeSat missions. However, further testing under simulated space conditions is necessary to comprehensively assess and validate its performance.

Shape memory polymer composites (SMPCs) are an intelligent class of materials capable of self-actuation, offering promising applications in diverse stimuli-responsive material systems. This study developed epoxy-based SMPCs reinforced with carbon–aramid fibers at a 15:85 ratio, with their glass transition temperature (T_g) tailored by incorporating 5 wt.% (SMPC-5) and 10 wt.% (SMPC-10) polyethylene glycol (PEG-600). Dynamic mechanical analysis (DMA) confirmed that PEG addition effectively reduced the T_g from 89.79 °C in the neat composite (SMPC-P) to 70.28 °C in SMPC-5 and 59.34 °C in SMPC-10. Incorporating 5 wt.% PEG enhanced storage and loss moduli, whereas excessive plasticization at 10 wt.% reduced stiffness. Infrared spectroscopy analysis revealed shifts and increased intensities in hydroxyl (OH), aliphatic C-H, and carbonyl (C=O) groups, indicating enhanced intermolecular interactions and bond formation. Tensile testing showed that the carbon–aramid filler significantly improved tensile strength and stiffness, with SMPC-10 achieving the highest tensile strength (233.59 MPa) and SMPC-5 the highest Young’s modulus (14.081 GPa). These results highlight the complementary role of carbon–aramid reinforcement and PEG plasticization in tuning thermomechanical behavior, providing baseline insights for designing SMPCs with tailored actuation and reliable structural performance.

This study evaluated the ballistic performance and failure mechanisms of epoxy-based hybrid laminates reinforced with abaca/UHMWPE and pineapple leaf fiber (PALF)/UHMWPE fabrics fabricated by using vacuum-assisted hand lay-up. Ballistic tests utilized 9 mm full metal jacket (FMJ) rounds (~426 m/s impact velocity) under NIJ Standard Level IIIA conditions (44 mm maximum allowable BFS). This experimental test was complemented by finite element analysis (FEA) incorporating an energy-based bilinear fracture criterion to simulate matrix cracking and fiber pull-out. The results showed that abaca/UHMWPE composites exhibited lower backface signature (BFS) and depth of penetration (DOP) values (~23 mm vs. ~42 mm BFS; ~7 mm vs. ~9 mm DOP) than PALF/UHMWPE counterparts, reflecting superior interfacial adhesion and more ductile failure modes. Accelerated weathering produced matrix microcracking and delamination in both systems, reducing overall ballistic resistance. Scanning electron microscopy confirmed improved fiber–matrix bonding in abaca composites and interfacial voids in PALF laminates. The FEA results reproduced major failure modes, such as delamination, fiber–matrix debonding, and petaling, and identified stress concentration zones that agreed with experimental observations, though the extent of delamination was slightly underpredicted. Overall, the study demonstrated that abaca/UHMWPE hybridcomposites offer enhanced ballistic performance and durability compared with PALF/UHMWPE laminates, supporting their potential as sustainable alternatives for lightweight protective applications.