Design and shape optimization of PolyJet bellows actuators

With regard to future robotic systems, the combination of Additive Manufacturing (AM) and pneumatic actuation yields multiple opportunities. Bellows actuators are exceptionally suitable for AM as the required geometrical complexity can easily be obtained and their functionality is not affected by rough surfaces and small dimensional accuracy. In this paper, multi-material PolyJet printable linear bellows actuators are presented. A design strategy based on finite elements analysis and numerical shape optimization is proposed and validated by experimental testing under quasi-static and repeated loading conditions. The presented results are useful for researchers and engineers considering the application of AM soft material bellows actuators for robots and other dynamic systems.