Overcoming Material and Process Challenges in 3D-printed Terahertz Components

Additive manufacturing (AM), commonly known as 3D-printing, provides a cost-effective approach for manufacturing of prototypes. The authors illustrate material analysis of suitable 3D-printable materials that can be used to manufacture THz components and investigate and provide solutions to challenges occurring during the 3D printing process. Samples in this study are 3D-printed using fused filament fabrication (FFF) based 3D-printers Ultimaker S5 and Bambu Lab X1E. We investigate a total of six materials: High Impact Polystyrene (HIPS), High Density Polyethylene (HDPE), Cyclic Olefin Copolymer (TOPAS), Polypropylene (PP), Polycarbonate (PC) and Polytetrafluoroethylene (PTFE/ Teflon). We observed that the Teflon material contains PC as material dopant to reduce the melting temperature. The authors observed warping of the 3D-structure due to the poor adhesion of material on the print-bed. An adhesive fluid or adhesive sheet applied on the print-bed before 3D-printing provides proper adhesion. Air gaps formed between the adjacent layers during the 3D-printing results into incorrect evaluations. The 3D-printing setting of material flow ratio above 100% ensures the filling of air gaps created due to layer-by-layer manufacturing. Moreover, the direction of nozzle movement also helps in achieving uniformity in 3D-printed sample. A minimal layer height of 100 µm for the 3D-printing of all the materials provides promising adhesion and better finish. Some materials e.g., PP, PC, TOPAS capture humidity, therefore the authors used specialized chambers to maintain low humidity during the whole 3D-printing process. Fan speed, low surrounding temperature contribute in blocking of the nozzles or premature cooling of the samples; therefore, it is necessary to maintain the temperature during 3D-printing. We investigated these samples using THz-TDS setup to find the most suitable material for AM of THz-components. The results reveal that the absorption coefficient of TOPAS is the least (α < 0.5 per cm at 0.4 THz) among all the investigated materials. Therefore, with the help of material analysis of 3D-printable materials for manufacturing of THz-components, the authors introduce fundamental research results for the future developments in the field of 3D-printing of THz components. [1] A. Shrotri, A. K. Mukherjee et. al.: Additive manufacturing and characterization of hollow core metal and topas waveguides for Terahertz sensor systems, 2023 IRMMW-THz, Montreal, QC, Canada, doi: 10.1109/IRMMW-THz57677.2023.10299134. [2] A. Shrotri, S. Joshi et. al.: THz-Characterization of Inkjet Printable Polymers,2025 French-German THz Conference, Siegen, Germany, 2025 [3] A. Shrotri, A. K. Mukherjee, et. al.: THz-Characterization of Additively Manufactured Spiral Shaped Waveguides, 2023 IEEE APCAP, Guangzhou, China, 2023, pp. 1-2, doi: 10.1109/APCAP59480.2023.10469842 [4] S. Joshi, A. Starsaja, et. al.: Additively Manufactured Terahertz Waveguides, 2025 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Helsinki, Finland, 2025, pp. 1-2, doi: 10.1109/IRMMW-THz61557.2025.11320095 [5] A. Shrotri, S. Joshi, et. al.: Terahertz Axicon Lenses, 2025 50th IRMMW-THz, Helsinki, Finland, 2025, pp. 1-2, doi: 10.1109/IRMMW-THz61557.2025.11319870