Model-guided design framework for robotic shape memory metastructures

Smart materials such as shape memory polymers (SMPs) offer a promising route to programmable, stimulus-responsive robotic structures. This study proposes a systematic design framework for the design of such robotic structures using thermally actuated SMPs, specifically polylactic acid (PLA). A building block library of 2D structures—straight beams, curved beams and triangles—was evaluated with finite element analysis (FEA) and experimental validation. A sensitivity analysis was performed to identify geometric parameters influencing deformation and recovery behaviour. The numerical analysis results of building block behaviour were validated with experimental tests, using PLA printed structures. A library was created, enabling metastructures to be formed through model-guided design. These metastructures are able to exhibit programmable and predictable deformation in a single direction by combining rigid and deformable elements. The results demonstrate the feasibility of the proposed design approach for creating thermally actuated SMP metastructures that exhibit robot-like behaviour.