Exploiting imperfections in thin shells for soft robotics

Imperfect shell and its associated output

Bi-shell valve characteristics using an imperfect shell and a spherical cap

Description

Elastic thin shells are well-known for their highly unstable post-buckling, a response that
exhausts their pressure bearing capacity and leads to catastrophic collapse. However, by using axisymmetric imperfections, thin shells can escape the classical bifurcation of perfect spherical shells. Due to the imperfection, the shells can exhibit multiple buckling modes containing each unique properties. By optimizing the geometrical parameters of the shell and its defects, it is possible to program the post-buckling characteristics and transition between buckling modes, thus offering potential routes for the design of soft metamaterials with application to soft robotics and other sectors.

Relevant publications 

Qiao C, Liu L, Pasini D, Bi-shell valve for fast actuation of soft pneumatic actuators via shell snapping interaction, Advanced Science, 2100445, 2021. 

Qiao C, Liu L, Pasini D, Elastic thin shells with large axisymmetric imperfection: from bifurcation to snap-through buckling, Journal of the Mechanics and Physics of Solids, Vol 141, 103959, 2020.