The use of additive manufacturing (AM) has moved well beyond prototyping and has been established as a highly versatile manufacturing method with demonstrated potential to completely transform traditional manufacturing in the future. In this paper, a comprehensive review and critical analyses of the recent advances and achievements in the field of different AM processes for polymers, their composites and nanocomposites, elastomers and multi materials, shape memory polymers and thermo-responsive materials are presented. Moreover, their applications in different fields such as bio-medical, electronics, textiles, and aerospace industries are also discussed. We conclude the article with an account of further research needs and future perspectives of AM process with polymeric materials.

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The quasi-static flexural and impact performance, up to projectile impact velocities of about 270 m s -1 , of fibre metal laminates (FMLs), which consist of relatively thin, alternately stacked, layers of an aluminium alloy and a thermoset glass fibre epoxy composite, have been investigated. The effects of varying (a) the yield strength, tensile strength and ductility of the aluminium alloy layer, (b) the surface treatment used for the aluminium alloy layers and (c) the number of layers present in the FML have been studied. It was found that increasing the strength of the aluminium alloy increases the quasi-static flexural strength of the FML, providing that good adhesion is achieved between the metal and the composite layers. Further, increasing the number of alternating layers of the aluminium alloy and fibre composite also somewhat increases the quasi-static flexural properties of the FML. In contrast, increasing the strength of the aluminium alloy had relatively little effect on the impact perforation resistance of the FML, but increasing the number of alternating layers of aluminium alloy and fibre composite did significantly increase the impact perforation resistance of the FML. The degree of adhesion achieved between the layers had only a negligible influence on the impact perforation resistance.

Gallium and its alloys, such as eutectic gallium indium alloy (EGaIn), a form of liquid metal, have recently attracted the attention of researchers due to their low toxicity and electrical and thermal conductivity for biomedical application. However, further research is required to harness EGaIn-composites advantages and address their application as a biomedical scaffold. In this research, EGaIn-polylactic acid/ polycaprolactone composites with and without a second conductive filler, MXene, were prepared and characterized. The addition of MXene, into the EGaIn-composite, can improve the composite's electrochemical properties by connecting the liquid metal droplets resulting in electrically conductive continuous pathways within the polymeric matrix. The results showed that the composite with 50% EGaIn and 4% MXene, displayed optimal electrochemical properties and enhanced mechanical and radiopacity properties. Furthermore, the composite showed good biocompatibility, examined through interactions with fibroblast cells, and antibacterial properties against methicillin-resistant Staphylococcus aureus. Therefore, the liquid metal (EGaIn) polymer composite with MXene provides a first proof-of-concept engineering scaffold strategy with low toxicity, functional electrochemical properties, and promising antimicrobial properties.

Conformal load-bearing antenna structures (CLAS) have been attracting the attention of aerospace industries in recent years. This type of multifunctional structures combines the features of conventional antennas with load-bearing capacity and has important applications in military and commercial airplanes especially for Unmanned Aerial Vehicles (UAVs). Equiangular slot spiral antennas are an alternative to traditional rectangular slots because of its wideband radiation characteristics. However, the mechanical characteristics of such a spiral antenna integrated into a structure are so far largely unexplored. In this paper, the electromagnetic (scattering parameter, radiation pattern and gain) and mechanical properties (stress concentration factor (SCF)) of spiral antennas is investigated using finite element analysis (FEA). The results lead to a recommendation for using this type of antenna for future CLAS concepts.

In this paper the feasibility of using a circular microstrip patch antenna to detect strain in composite plates and the effects of different materials on sensitivity of the patch antenna are investigated. Also the effect of strain direction on the frequency shift is studied. The theoretical model shows a linear relationship between strain and the shift in the resonant frequency of the antenna in any material. A circular microstrip patch antenna is designed and fabricated to work at 1.5GHz and attached to three different materials for testing. Both Finite Element Analysis (FEA) and experimental tests have been undertaken to corroborate the relationship between strain and frequency shift. The ultimate intention of this work is to configure antennas for the detection of relatively small damage zones in structures and to do so wirelessly.