Shape transition and multi-stability of helical ribbons: a finite element method study

Abstract

Helical structures are among the most universal building blocks in nature and engineering. In this work, I performed three-dimensional finite element simulations to study the transitions of shapes and multi-stability in the mechanically self-assembled helical structures driven by anisotropic misfit strains. The shape transition between a purely twisted ribbon, or a helicoid, and a general helical ribbon can be achieved by tuning a few relevant geometric and mechanical parameters, including the misfit strains, the geometric misorientation angle, the dimensions, and the mechanical properties of the composite layers. The results of our work show good agreement with the recent theoretical works and will serve as a powerful tool to facilitate on-demand designs of spontaneously curved structures at both macroscopic and microscopic scales, for a number of engineering applications including nanoelecromechanical systems, drug delivery, sensors, drug delivery, active materials, optoelectronics, and microrobotics.