Abstract
This study presents the design and development of a compact in-situ microwave curing module for a customized 3D printer. The device converges electromagnetic radiation at the nozzle to allow localized and volumetric heating of freshly extruded geopolymer materials. Microwave energy transmission is through dipolar polarization, ionic conductivity, and interfacial polarization mechanisms, and thus accelerates early-stage hydration and geopolymerization reactions. It is found that selective exposure enhances buildability, inter-layer bonding strength, and geometric stability by reducing slump and deformation during the printing process. Unlike conventional thermal curing, microwave-assisted curing minimizes losses by direct radiation-to-matter coupling, achieving greater energy efficiencies and life-cycle cost metrics. Uniform internal heating is used to reduce temperature gradients and shrinkage-induced cracking, whereas microstructural consolidation is integrated by adjusting thermal and non-thermal microwave action. Preliminary results show a promising outcome in enhancing mechanical strength in geopolymer samples. The findings project a future direction towards scalable, energy-efficient, and structurally superior 3D construction printing technology with low-carbon binder chemistries.