Ongoing research in computational design synthesis of passive dynamic systems aims to automatically generate robotic configurations based on a given task. However, an automated design-to-fabrication process also requires a flexible fabrication method. This paper aims to explore designing and fabricating passive dynamic walking robots and all necessary components using single-material fused deposition modeling (FDM). Being able to fabricate all components of a robot using FDM is a step toward the goal of automated design and fabrication of passive dynamic robots.
Two different configurations of passive dynamic walking robots are re-designed to be fabricated using FDM. Different robotic joint assemblies are designed and tested. To arrive at feasible solutions, a modular design approach is chosen and adjustability of components after printing is integrated in the design.
The suitability of FDM for printing passive dynamic robots is shown to depend heavily on the sensitivity of the configuration. For one robot configuration, all components are printed in one job and only little assembly is needed after printing. For the second robot configuration, which has a more sensitive gait, a metal bearing is found to increase the performance substantially.
Printable, monolithic mechatronic systems require multi-material printing, including electronics. In contrast, passive dynamic systems not only have the potential to save energy and component cost compared to actuated systems but can also be fabricated using single-material FDM as demonstrated in this paper.
