A precise controlled shape change of responsive materials requires the development of theoretical and computational approaches capable of reproducing the involved physical phenomena and their interaction. When polymer-based materials are considered, shape change capabilities can be obtained from external stimuli, such as temperature, light, humidity, electric field, etc. These stimuli, if precisely spatiotemporally controlled, can deform a structure into a desired configuration in a given time. The paper investigates the multiphysics-based driven shape change in highly deformable composite structures made of a passive elastic structure and an active one capable of responding to environmental stimuli. By harnessing different mechanisms, namely 1) the swelling of gels [1] and 2) the deformation of electro-active dielectric elastomers (DE) [2], controlled mechanical stresses can be transmitted to the passive portion leading to its deformation. In the present study, an elastic tube filled with a gel, whose volume deformation is driven by the fluid uptake [3], and a bilayer structure made of an elastic substrate and a DE active layer, whose deformation is induced by an electric potential [4], are considered as morphing structures. It is shown that by properly distributing the mechanical properties in the hyperelastic passive element interacting with the responsive active material, a precise shape change can be achieved. To this end, we numerically solve the multyphysics coupled problems and adopt a machine learning (ML) approach for solving the inverse problem. Given a prescribed target shape, the proposed approach enables to obtain the proper spatial stiffness distribution of the passive elastic element enabling the achievement of the desired deformed configuration.
REFERENCES
[1] Chester, S. A., and Anand, L. (2010) A coupled theory of fluid permeation and large deformations for elastomeric materials. Journal of the Mechanics and Physics of Solids 58, 1879-1906.
[2] Dorfmann, L., & Ogden, R. W. (2023). The nonlinear theory of magnetoelasticity and the role of the Maxwell stress: a review. Proceedings of the Royal Society A, 479(2278), 20230592.
[3] Monchetti, S., Brighenti, R., Hanuhov, T., and Cohen, N. (2024) Controlled swelling-induced shape change of soft gel filled structures. Thin-Walled Structures 204, 112280.
[4] Cohen, N. (2017) Enhancing the electro-mechanical response of stacked dielectric actuators. Journal of Elasticity 127, 103-113.
| Subject : | : | oral |
| Topics | : | 1-8 - Mechanics of active and coupled materials |
| PDF version | : |  PDF version |
