🤖 AI Summary
This study addresses the design challenge of balancing manufacturing robustness with arbitrary directional bending in multi-directional soft pneumatic actuators by proposing a systematic topology optimization method. The approach introduces a three-field formulation to ensure manufacturing robustness and incorporates Darcy’s law with a drainage term to model design-dependent loads. Furthermore, a minimax optimization model based on target deformations is constructed and efficiently solved using the method of moving asymptotes. The resulting high-performance, unconventional geometries are validated through numerical simulations, which confirm that the optimized actuators successfully achieve flexible multi-directional motion capabilities in three-dimensional space. This work provides a new paradigm for the innovative structural design of soft robots.
📝 Abstract
Soft pneumatic actuators (SPAs) are highly promising and have been extensively explored within the field of soft robotics. Under pneumatic pressure loads, an SPA undergoes bending deformation to perform specific tasks. A multi- or omni-directional SPA can bend and move in any direction within a 3D space, leveraging its multiple degrees of freedom to realize various mechanical functions. This work presents a systematic methodology using topology optimization (TO) to achieve an optimized design for a multi-directional SPAs. To ensure manufacturing robustness, a three-field TO formulation considering blueprint, dilated, and eroded designs is implemented. Additionally, Darcy's law, incorporating a drainage term, is used to model the design-dependent nature of the pneumatic loading. A min-max optimization problem is formulated based on the target output deformations of the SPA unit and solved using the Method of Moving Asymptotes. The optimization yields a high-performing, unconventional geometric design. Finally, numerical simulations demonstrate that the optimized SPA successfully achieves versatile multi-directional movements.