Design of an Additively Manufacturable Multi-Material Light-Weight Gripper with integrated Bellows Actuators

Abstract

Combining state-of-the-art additive manufacturing technologies with structural optimization has the potential to produce geometrically complex multi-material components with integrated functionalities and desired structural behavior. In this article, the simulation-driven design process of a multi-material lightweight gripper with an integrated pneumatic bellows actuator is described. The design of the bellows structure is based on a previously published contribution to the RoboSoft2018 conference in Livorno, Italy. The conference paper contains the shape optimization and experimental investigations of the structural and fatigue behavior of linear type multi-material PolyJet bellows actuators. In this extended version, the main findings of the conference paper are translated into the design of a rotary type bellows actuator that is finally integrated into a multi-material lightweight gripper. In order to define the layout of the gripper's support structure, a density-based topology optimization is performed and the application on a PolyJet printed lightweight robot is demonstrated. The presented design approach and results are useful for researchers and engineers involved in the development of multimaterial additive manufacturing, simulation-driven design and functionally integrated structures for pneumatic robotic systems.

PolyJet-Printed Bellows Actuators: Design, Structural Optimization, and Experimental Investigation

“…Because force responses to imposed displacements were observed to be significantly time dependent, this extended version is enhanced with relaxation tests of elastomeric bellows structures. The relevance of the presented results for the development of a multi-material light-weight gripper is presented demonstrated in another extended version paper (Dämmer et al, 2019 ). The presented results contribute to the general knowledge concerning the use of PolyJet elastomers for pneumatic actuators and robots.…”

Design of an Inkjet-Printed Rotary Bellows Actuator and Simulation of its Time-Dependent Deformation Behavior

“…Dämmer et al ( Dämmer et al, 2019a ) used A30 and T+ in combination with Vero materials to produce the linear bellows actuators shown in Figure 2A and investigated the effects of material and shape variations on their fatigue and deformation behavior. In a subsequent publication, Dämmer et al ( Dämmer et al, 2019b ) transferred their findings to rotary bellows chambers of similar materials and demonstrated their integration into a robotic lightweight gripper; Figure 2B shows the chamber design, which comprises four elastomeric bellows segments connected by three rigid frames and a roller guide system that prevents excessive deformation. The specific shape of the bellows segments is based on conceptual Finite Element (FE) simulations ( Dämmer et al, 2019b ).…”

“…In a subsequent publication, Dämmer et al ( Dämmer et al, 2019b ) transferred their findings to rotary bellows chambers of similar materials and demonstrated their integration into a robotic lightweight gripper; Figure 2B shows the chamber design, which comprises four elastomeric bellows segments connected by three rigid frames and a roller guide system that prevents excessive deformation. The specific shape of the bellows segments is based on conceptual Finite Element (FE) simulations ( Dämmer et al, 2019b ). With the objective of strain homogenization, local wall thicknesses were tuned within multiple iterations of design and analysis.…”

Investigations on the Processing of Ceramic Filled Inks for 3D InkJet Printing

“…For example, when it comes to printing ever smaller structures [10,11] or simplifying the process by using physical conditions to meet economic requirements [12,13]. 3D inkjet printing differs from the above-mentioned production methods in that it allows several materials to be deposited in one process step, which could enable the production of fully functional and complete components in one printing process [14][15][16]. Layer by layer, a low-viscosity material is usually dispensed from a drop-on-demand print head via piezoelectric actuation.…”

“…To further increase the potential of 3D inkjet printing, the technology is moving from rapid prototyping to rapid manufacturing [14,15]. This creates a demand for components with suitable mechanical properties.…”