In this study, fused filament fabrication (FFF) printing parameters were optimized to improve the surface quality and reduce the printing time of Acrylonitrile Butadiene Styrene (ABS) polymer using the Analysis of Variance (ANOVA), it is a statistical analysis tool. A multi-objective optimization technique was employed to predict the optimum process parameter values using particle swarm optimization (PSO) and response surface methodology (RSM) techniques. Printing time and surface roughness were analyzed as a function of layer thickness, printing speed and nozzle temperature. A central composite design was preferred by employing the RSM method, and experiments were carried out as per the design of experiments (DoE). To understand the relationship between the identified input parameters and the output responses, several mathematical models were developed. After validating the accuracy of the developed regression model, these models were then coupled with PSO and RSM to predict the optimum parameter values. Moreover, the weighted aggregated sum product assessment (WASPAS) ranking method was employed to compare the RSM and PSO to identify the best optimization technique. WASPAS ranking method shows PSO has finer optimal values [printing speed of 125.6 mm/sec, nozzle temperature of 221 °C and layer thickness of 0.29 mm] than the RSM method. The optimum values were compared with the experimental results. Predicted parameter values through the PSO method showed high surface quality for the type of the surfaces, i.e., the surface roughness value of flat upper and down surfaces is approximately 3.92 µm, and this value for the other surfaces is lower, which is approximately 1.78 µm, at a minimum printing time of 24 min.

The most common method to fabricate both simple and complex structures in the additive manufacturing process is fused deposition modeling (FDM). Many researchers have studied the strengthening of FDM components by adding short carbon fibers (CF) or by reinforcing solid carbon fiber rods. In the current research, we sought to enhance the mechanical properties of FDM components by adding bioinspired solid CF rods during the fabrication process. An effective bonding interface of bioinspired CF rods and polylactic acid (PLA) was achieved by triangular interlocking sutures and by employing synthetic glue as the binding agent. In particular, the tensile strength of solid CF rod reinforced PLA samples was studied. Critical parameters such as layer thickness, extruder temperature, extruder speed, and shell thickness were considered for optimization. Significant process parameters were identified through leverage plots using the response surface methodology (RSM). The optimum parameters were found to be layer thickness of 0.04 mm, extruder temperature of 215 °C, extruder speed of 60 mm/s, and shell thickness of 1.2 mm. The results revealed that the bioinspired solid CF rod reinforced PLA (CFRPLA) composite exhibited a tensile strength of 82.06 MPa, which was approximately three times higher than the pure PLA (28 MPa, 66% lower than CFRPLA), acrylonitrile butadiene styrene (ABS) (28 MPa, 66% lower than CFRPLA), polyethylene terephthalate glycol (PETG) (34 MPa, 60% lower than CFRPLA), and nylon (34 MPa, 60% lower than CFRPLA) samples.

Fused deposition modeling (FDM) is a contemporary approach that can produce simple and complex physical models, prototype tools, and functional components. However, the challenge is choosing the right parameters, which are essential to printing a high-quality Additive Manufactured (AM) structure with acceptable mechanical attributes, like mechanical strength. In the additive manufacturing technique, fabricating a lightweight structure without compromising the weight and shape is very difficult because the significant parameter is infill density (D) %, which is directly proportional to the strength and inversely proportional to the weight. In this research based on morphogenesis, the infill density is varied at different locations wherever it is needed to print a lightweight, high-strength structure. Parameters Layer Thickness (LT), Shell Thickness (ST), and D were chosen, and experiments were conducted as per Central Composite Design (CCD). Tensile Strength (TS) and Compression Strength (CS) samples were printed with PLA and tested. The results were used to develop a multi-objective function. To predict maximum TS and CS without compromising the weight, Particle Swarm Optimization (PSO) and Response Surface Methodology (RSM) techniques were used to solve the multi-objective function. PSO predicts that the optimum printing parameter values for achieving a lightweight, high-strength structure are LT of 0.17 mm, ST of 0.91 mm, and D of 11.3%. These predicted results were confirmed through experiments.

The quest for novel and sustainable fibres presents a significant challenge in researching composite materials. In this study, the viability of weaver bird nests has been investigated as a hybrid fibre source for composite production. Each nest has exhibited unique variations in fibre composition and structure, reflecting the availability of diverse fibres in their respective environments. These nests are meticulously integrated with an epoxy resin matrix to create composites (designated as N1, N2, and N3). Mechanical properties such as tensile strength, flexural strength, hardness, water absorbency, and low-impact resistance have been evaluated to assess the performance of hybrid fibre composite materials. Additionally, wear testing is conducted using a pin-on-disc machine with varying loads (20, 30 and 40 N) and a fixed radius of 50 mm. Interestingly, the nest collected from the village, comprising five different plant fibres, has demonstrated superior mechanical and tribological properties (N2) compared to other nest fibres. Conversely, the N1 and N3 composites have exhibited diminished mechanical performance, attributed to a limited variety of fibres and a looser braiding structure. These findings suggest that the natural Voronoi design of hybrid bundle fibres holds promise as a potential source for polymer composites. However, the study emphasizes the critical role of fibre selection and the potential benefits of exploring natural sources for advanced composite materials development. Furthermore, this research underscores the importance of sustainable fibre procurement and illustrates the potential of biomimicry in the research of composite materials.