Mechanical response of multistable tensegrity-like lattice chains

Recent developments in the quality and accuracy of additive manufacturing have drawn particular attention to metamaterials characterised by a multistable response to achieve exceptional mechanical properties. This work focuses on the design, fabrication, testing, and simulation of tensegrity-like lattice chains accomplishing a multistable behaviour. The chains are composed of chiral tensegrity-like units featuring a highly nonlinear bistable response with compression-twisting coupling. Different chains are designed by exploiting the chirality of the units and realised by the inverted stereolithography technique. Their mechanical response is experimentally characterised, demonstrating the attainment of the desired multistable behaviour. A predictive semi-analytical model is derived to reconstruct the multistable energy landscape and force-vs.-displacement curve of the whole chain. The presented chains may constitute a flexible platform for programmable materials, potentially extending to modular chains also based on other types of tensegrity-like units.