Bending instability of island-bridge structures

As key structures in medical technology, soft robotics, and flexible electronics, the mechanical behavior of island-bridge structures has drawn great attention among the scientific community. However, the bending instability properties of island-bridge structures are still unclear, which hinders their function realization and design. Herein, the bending behavior of the island-bridge structure is comprehensively explored by experiment, numerical simulation, and theoretical analysis. It is found that the island-bridge structures can produce upward or downward morphologies under the bending loads, which is attributed to the coupling effect of combined loadings on the upper films. The bending morphology and the critical load can be well tuned by changing the corresponding material and geometric parameters or introducing creases in the upper film. The results should be of significant importance for the development of flexible electronics, soft robots, and biomedical engineering and enrich our knowledge of the mechanical properties of the island-bridge structure.