A new shared paper on "Development of a Material Design Space for 4D-Printed Bio-Inspired Hygroscopically Actuated Bilayer Structures with Unequal Effective Layer Widths" has been published in Biomimetics. This paper presents a material design space to find new material combinations that takes into account unequal effective widths of the layers, as commonly used in fused filament fabrication, and deflections under self-weight.
Abstract
Significance of geometry for bio-inspired hygroscopically actuated bilayer structures is well studied and can be used to fine-tune curvatures in many existent material systems. We developed a material design space to find new material combinations that takes into account unequal effective widths of the layers, as commonly used in fused filament fabrication, and deflections under self-weight. For this purpose, we adapted Timoshenko’s model for the curvature of bilayer strips and used an established hygromorphic 4D-printed bilayer system to validate its ability to predict curvatures in various experiments. The combination of curvature evaluation with simple, linear beam deflection calculations leads to an analytical solution space to study influences of Young’s moduli, swelling strains and densities on deflection under self-weight and curvature under hygroscopic swelling. It shows that the choice of the ratio of Young’s moduli can be crucial for achieving a solution that is stable against production errors. Under the assumption of linear material behavior, the presented development of a material design space allows selection or design of a suited material combination for application-specific, bio-inspired bilayer systems with unequal layer widths.
Congratulations to the joint first authors Friederike Krüger (Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg) and Rebecca Thierer (IBB) and co-authors Yasaman Tahouni (ICD), Renate Sachse, Dylan Wood (ICD), Achim Menges (ICD) Manfred Bischoff (IBB) and Jürgen Rühe (Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering,University of Freiburg).
Please find the full open access paper here.