Deterministic snap-through buckling and energy trapping in axially-loaded notched strips for compliant building blocks

Harnessing elastic instabilities has enabled recent advances in new classes of materials and devices due to the characteristics of amplifying force and augmented motion. Achieving these enhanced effects usually relies on using buckled beam or strips as the building block. In response to such a need, we investigate the contact-induced energy trapping of axially-loaded strips. To achieve the feature of energy trapping, we implement an "imperfection by design" approach to trigger a controllable and predictable interactive buckling in axially-loaded strips. By combining finite-element simulations and desktop-scale experiments, we found that the contact of strip elements can be induced by strategically controlled the number, the location and the layout of local predefined geometric defects, leading to a deterministic on-demand snap-through buckling response compared to the ones without such geometric defects. Our study thereby opens avenues for the design of the next generation of compliant mechanisms with high fidelity and low sensitivity over a wide range of length scales.