In this report, we investigate the infusion of carbon dioxide into a 3D-printable photosensitive polymer. The result is a carbonated polymer composite material. In use, polymer composite materials expect to succeed where ordinary polymers and metals fail. This is due to the tailorability of composite materials for specific applications. Usually, micro/nano-particulates are embedded as fillers within a polymer matrix, enhancing the overall material properties. Here, carbon dioxide (CO₂) microbubbles serve as the filler within a nylon-like polymer matrix. Additive manufacturing by stereolithography (SLA) of the carbonated polymer composite proved possible using the digital light projection (DLP) 3D printing technique. Post-heat treatment using thermogravimetric analysis of the samples at elevated temperatures resulted in a 33% mass reduction, indicative of nearly complete solvent removal and curing. An initial increase in polymer carbonation duration showed a 16% increase in porosity, more stable thermal profiles, and a 40% decrease in specific heat capacity. Thermo-mechanical compressive tests on an optimal carbonated sample revealed a 70% increase in compressive strength over its neat counterpart and a peak modulus at 50 °C of 60 MPa. Such 3D-printable carbonated polymer composites may find use in applications requiring high strength-to-weight ratio thermally stable polymers and applications requiring a versatile and convenient storage medium for on-demand CO₂ deposition or supercritical fluid phase transformation.

Porosity is the physical feature of certain materials that describes the voids in their microscale structure and are present to some degree within additive manufactured (AM) parts and materials. Properties such as light transmission, weight, conductivity, and strength are dependent on the porosity of a material. Of the various methods to produce porosity, gas compression and

Fifth generation (5G) network considerably improves communication capabilities and has therefore caught the attention of researchers, industry and government. Owing to its desirable bandwidth, front end miniaturized radio frequency components, low interference and high resolution, it is considered a potential candidate for high-speed communication services. Additive manufacturing on the other hand, has changed how products are developed owing to its low cost and part customization capability. Diverse printing techniques and materials further allow for new substrate properties when designing patch antennas. Thus, it can be used as an option to fabricate sub-6 GHz antenna devices. The present work studies a method where substrates made of a commercial resin are imprinted with nickel films for planar, compact, low-profile patch antennas with the aid of separately printed template patterns and electrodeposition. The electrical and material integrity of antennas are characterized to determine which process parameter(s) offer optimum fabrication. Simulations were carried out using ANSYS High-Frequency Structure Simulator (HFSS®) to optimize both slot and non-slot patch antennas prior to fabrication. The antennas are found to be operable at 6.9 GHz and 5.8 GHz respectively with bandwidths of 0.77 and 1.77 GHz. The antennas via our novel method have a potential for mobile applications, particularly WLAN and 5G networks.