Transitions of nanostructure-induced bistable disks actuated by line forces

The transition processes of nanostructure-induced bistable disks triggered by line forces are analytically and experimentally investigated. An analytical model based on the Ritz method is formulated to optimise the placement of axisymmetric line forces for converting the bistable disks between the two stable configurations. Different transition paths are captured for the bistable disks upon applying the line forces at different locations. The transition features, including the snapping forces and transition types, of the bistable disks under different line forces are analysed with respect to the design parameters, such as the nanostructured region ratio, accumulated plastic deformation and disk slenderness. Strategies for placing the line forces to achieve the shape transitions using small line forces or small total forces are proposed. Transition tests of manufactured bistable disks reveal a local buckling phenomenon when the line forces are placed around the disk centre, which is also predicted by numerical modelling. The experimental investigation validates the analytical studies, which are also verified by numerical models. This study provides information for the design of mechanical actuations to achieve the shape reconfiguration of bistable disks.