Variable stiffness structure inspired by seashells

Abstract

Variable stiffness is typically employed in soft robotics to address the trade-off between compliance and the ability to generate stability when required. Among the several approaches investigated, jamming transition systems show remarkable stiffness performance and fast response. Building upon the preliminary study on a seashell bioinspired variable stiffness structure, here we extend the design space through a parametric study supported by a finite element model based on commercially available software. The study allows establishing the relationship between the design parameters and the stiffness performance. Moreover, the optimal configuration in terms of performance to energy consumption is identified and compared to previous similar approaches. Finally, the low computational cost of the finite element model demonstrated to be an effective tool for the analysis of complex geometries, thereby establishing a foundation for the development of cost-effective and lightweight soft robotic devices empowered by variable stiffness capabilities (e.g. a wearable device for assistance).