Metamaterials are architected cellular materials, also known as lattice materials, that are inspired by nature or human engineering intuition, and provide multifunctional attributes that cannot be achieved by conventional polymeric materials and composites. There has been an increasing interest in the design, fabrication, and testing of polymeric metamaterials due to the recent advances in digital design methods, additive manufacturing techniques, and machine learning algorithms. To this end, the present review assembles a collection of recent research on the design, fabrication and testing of polymeric metamaterials, and it can act as a reference for future engineering applications as it categorizes the mechanical properties of existing polymeric metamaterials from literature. The research within this study reveals there is a need to develop more expedient and straightforward methods for designing metamaterials, similar to the implicitly created TPMS lattices. Additionally, more research on polymeric metamaterials under more complex loading scenarios is required to better understand their behavior. Using the right machine learning algorithms in the additive manufacturing process of metamaterials can alleviate many of the current difficulties, enabling more precise and effective production with product quality.

Metamaterials, also known as lattice‐structured materials, imitate the multifunctionality of natural architects as tailoring their physical properties is associated with manipulating their microstructure. As the recent evolution of additive manufacturing enables the creation of intricate geometries with minimal material wastage, improving the design to manufacturing cycle of lattice structured materials has become one of the trending research areas. Triply periodic minimal surface (TPMS) and plate lattice materials are renowned for their exceptional mechanical behavior in lightweight applications. Apparently, several types of design optimization strategies are explored to maximize their performance for better biocompatibility and mechanical loading resistance. Some of these strategies include functional gradation and multimorphology hybridization that are comprehensively described in this review. Their benefits and drawbacks are highlighted with a focus on TPMS and plate lattice materials. The review anticipates the utilization of automated design exploration methods (i.e., topology optimization and data‐driven methods) to further enhance the design optimization procedure of lattice structured materials.

Terrestrial gamma ray flashes (TGF) are intense and prompt bursts of X- and gamma-rays of up to 100 MeV of energy. Typically associated with thunderstorm activity, TGFs are produced by bremsstrahlung effects of electrons accelerated in strong electric fields generated by lightning. TGFs can be effectively targeted by gamma detectors with enhanced time stamping capabilities onboard of satellites operating at near-Earth low obits (LEO). Light-1 is a miniature satellite, a 3U CubeSat designed to detect, monitor and study terrestrial gamma ray flashes in low Earth orbit. The two payload detectors are composed of a photomultiplier tube and silicon photomultipliers. The two detectors are mounted at two ends of the CubeSat and the proposed orientation of the CubeSat will ensure maximum TGF detection probability. To allow an increased frequency of data downlink, Khalifa University has collaborated with NanoAvionics Corp, and hence Light-1 has access to three ground stations situated across the map, Abu Dhabi in United Arab Emirates, Vilnius in Lithuania, and Aalborg in Denmark. The satellite expected to launch in late-2021 is currently in its assembly and integration phase. This paper describes mission, concept, objectives, success criteria, design, analysis, status, and the future plans of Light-1 satellite.

Pyroshock events during a Nanosatellite launch might lead to mission failure. Therefore, it is important to be able to simulate such events during mission design. This study introduces a procedure to perform the Nanosatellite qualification shock test using a metal-to-metal impact facility. Such a facility was constructed with a capacity to generate mechanical shock waves up to 10,000 g for an out of plane (OOP) impact, and 5000 g for an in-plane (IP) impact. Furthermore, several experiments were carried out to establish a calibrating procedure, for both the IP and the OOP impacts. The experiments showed that increasing the impactor mass will raise the amplitudes of the lower frequency region of the Nanosatellite Shock Response Spectrum (SRS) curve. Furthermore, increasing the impact velocity will introduce a higher impact energy to the SRS curve. A practical and a cost-effective solution was presented to overcome the IP excitation limitation, through using a commercial silicon rubber pad as an interface between the testpod and the resonating plate. This approach proved to be successful in rectifying the lower frequency region modes for the IP impact test. The measurements were successfully validated using the positive and negative SRS approach. The experimental setup was verified using 1D and 2D numerical elements via the commercially available finite element analysis software ABAQUS.