COMPARATIVE STUDY OF MATERIAL EXTRUSION AND VAT PHOTOPOLYMERIZATION ADDITIVE MANUFACTURING TECHNIQUE USING SQUARE BASE PYRAMID AS AN ARTIFACT AND APPLICATIONS

A comparative analysis of Material Extrusion and VAT Photopolymerization 3D printing is done using various geometrical models, including square base pyramid, co-centric circular stamps, and lattice structures. The pyramid with Council of Scientific and Industrial Research (CSIR) and National Physical Laboratory (NPL) logos, texts printed by both techniques is studied for its dimensional accuracy as per the process parameters. The 3D printed specimen by Material Extrusion measured an average layer thickness of ~ 104 µm and VAT Photopolymerization measured a layer thickness of ~ 54 µm. The calculated void volume of the printed pyramid due to the staircase effect is ~ 2.9 % for the Material Extrusion and ~ 0.14 % for the VAT Photopolymerization. Mechanical properties of ASTM D638 tensile test samples based on build orientation showed anisotropy for Material Extrusion, whereas VAT Photopolymerization printed test samples are isotropic. The degree of anisotropy (DOA) of 0.35, modulus of elasticity (MOE) of 1.7 GPa and ultimate tensile strength (UTS) of 62 MPa are measured for the Material Extrusion printed test sample. The ZXY build-oriented test sample showed the lowest values compared to all the other build orientations. Comparatively, the MOE and UTS for the VAT Photopolymerization printed samples are equal for all build orientations and are ~ 950 MPa and ~ 39 MPa, respectively. The applicability of the present comparison of 3D printing techniques is demonstrated through functionality studies of printed stamps for ring electrodes and lattice structures as templates. The active area of the Fused deposition modeling (FDM) printed ring electrodes for maximum resolution is 17 times larger compared to that of Digital light processing (DLP) printed stamps. Additionally, the mean pore size for FDM-printed lattice structures was found to be ~ 650 µm, while the lattice structure printed by DLP using Polyurethan acrylate resin exhibited a pore size of ~ 220 µm. This analysis evaluates the dependence of stamp size due to print resolution specific to the technique. The importance of this research lies in addressing the growing demand for optimized 3D printing processes in manufacturing applications, such as sensors, electrodes, and structural components. By comparing dimensional accuracy, surface finish, print resolution, and mechanical properties, this study offers valuable insights into how the selection of printing techniques and process parameters can significantly influence the final product's performance.