Cuts Guided Deterministic Buckling in Arrays of Soft Parallel Plates for Multifunctionality

Harnessing buckling instability in soft materials offers an effective strategy to achieve multifunctionality. Despite great efforts in controlling the wrinkling behaviors of film-based systems and buckling of periodic structures, the benefits of classical plate buckling in soft materials remain largely unexplored. The challenge lies in the intrinsic indeterminate characteristics of buckling, leading to geometric frustration and random orientations. Here, we report the controllable global order in constrained buckling of arrays of parallel plates made of hydrogels and elastomers on rigid substrates. By introducing patterned cuts on the plates, the randomly phase-shifted buckling in the array of parallel plates transits to a prescribed and ordered buckling with controllable phases. The design principle for cut-directed deterministic buckling in plates is validated by both mechanics model and finite element simulation. By controlling the contacts and interactions between the buckled parallel plates, we demonstrate on-demand reconfigurable electrical and optical pathways, and the potential application in design of mechanical logic gates. By varying the local stimulus within the plates, we demonstrate that microscopic pathways can be written, visualized, erased, and rewritten macroscopically into a completely new one for potential applications such as soft reconfigurable circuits and logic devices.