3D-printed antibacterial filters obtained via digital light processing exploiting surface microwaves functionalization with natural amino acids

3D printing based on Digital Light Processing (DLP) technology was used to develop antibacterial filters, combining design versatility and manufacturing precision. The advantages of 3D printing, including the ability to produce complex geometries, reduction of material waste, and rapid iteration between design and production, were exploited to make two different filter configurations. In addition, these geometries were analyzed by computational fluid dynamics (CFD) to evaluate and compare their effectiveness in terms of flow distribution and antibacterial potential. The filters were successfully printed using photosensitive resins based on polyethylene glycol diacrylate (PEGDA), acrylic acid (AA) and glycidyl methacrylate (GMA). Subsequently, they were subjected to functionalization processes that employed various chemical techniques and functional molecules, notably arginine and agmatine, which antibacterial activity has been widely demonstrated. These processes enabled the incorporation of specific groups aimed at bacterial adhesion and inactivation. Characterization of the degree of functionalization was conducted by spectroscopic and microscopic techniques, confirming the effectiveness of the surface treatment. Finally, the filters were tested against Gram-positive and Gram-negative bacteria to evaluate their antibacterial efficacy. Results showed a significant reduction in bacterial viability for agmatine-functionalized PEGDA/GMA-based filters, demonstrating that both filter design and functionalization play a crucial role in achieving high antibacterial performance. The results for the other filters, however, were uncertain, and further analysis will be needed. This study, however, confirms the potential of DLP technology, which, together with appropriate functionalization methods, suggests new possibilities for the development of customizable and functional devices.