Characterizing 3D-printed soft joints: material, temperature, and infill density analysis
DOI:
https://doi.org/10.17979/ja-cea.2026.47.13775Keywords:
Soft robotics, Smart structures, Mechatronic system modeling, design and optimization. , Advanced manufacturing and remanufacturing technologies, Robotic grasping and manipulationAbstract
This paper presents the mechanical characterization of tendon-driven, multi-segment soft joints fabricated via Fused Deposition Modeling (FDM), exploring internal infill density and active thermal foaming as primary tuning parameters. We systematically evaluate joints printed with Varioshore TPU—a foaming elastomer—across a thermal gradient and varying porous infill densities, comparing the results against a standard Filaflex 82A baseline. Tensile tests reveal that modulating infill density provides a predictable, non-linear amplification of structural stiffness. Furthermore, thermal activation of the foaming agent in Varioshore TPU drastically enhances mechanical resistance. Compared to Filaflex, the foamed Varioshore achieves superior absolute strength and a vastly broader tunable bandwidth. These findings demonstrate that active foaming filaments offer great versatility and provide a baseline for designers to program both delicate compliance and high rigidity from a single material.
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Copyright (c) 2026 Jaime González-Menocal, Emilia Adela Laber, Claudia Sánchez, Lisbeth Mena, Jorge Muñoz, Concepción A. Monje
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
