Folded Goursat surface and banana-shaped seedpod

TL;DR

This paper introduces a new family of isometric deformations inspired by a banana-shaped seedpod, enabling controlled opening and closing behaviors in thin vegetal shells for smart materials and soft actuators.

Contribution

It presents a novel analytical model of folded Goursat surfaces that mimic seedpod movements, enhancing design possibilities for soft actuators.

Findings

Optimal shapes for opening are the most elongated.

The model enables switching between horizontal and vertical closures.

The approach provides a new way to design shape-changing soft structures.

Abstract

Thin vegetal shells have recently been a significant source of inspiration for the de\text{sign} of smart materials and soft actuators. Herein is presented a novel analytical family of isometric deformations with folds, inspired by a banana-shaped seedpod, which converts a vertical closing into either an horizontal closing or an opening depending on the location of the fold. Similarly to the seedpod, optimum shapes for opening ease are the most elongated ones.