On the fabrication and mechanical modelling microscale bistable tensegrity systems

We report about the analysis, design, and experimental testing of modular structures composed of bistable units derived from the classic triangular tensegrity prism. Tensegrity structures are pin-connected frameworks, composed by bars and cables, possessing internal mechanisms and self-stress states, and featuring a variety of structural responses depending on their prestress, edge connectivity, and geometry. When a tensegrity system has only one internal mechanism and one self-stress state, as in the triangular prism case, it is possible to associate to it a corresponding bistable unit, by replacing all cables with bars and changing their edge-lengths slightly. After presenting experimental results of compression tests carried out on microscale specimens fabricated through multiphoton lithography, we compare them with the numerical predictions obtained by our computational model.