An explicit structural optimization method for temperature-sensitive hydrogel actuation devices

Abstract

Hydrogel actuation devices are commonly composed of responsive and passive materials, and their actuation effect depends on their unique structure. In this paper, an explicit optimization method is proposed for the design of temperature-sensitive hydrogel-based soft devices involving swelling and shrinking to achieve specific actuation effects. In this method, the outline of configuration and the responsive layer are explicitly described by the ordered B-spline curve and movable hydrogel patch, respectively. The parametric modeling method is proposed to construct the geometric model with local features, which can transform the complex patch stacking problem into the fusion problem of three-dimensional geometry. Based on the large deformation theory of temperature-sensitive hydrogel, the deformation behavior of soft device is accurately simulated. The adaptive mesh division method is applied to numerical simulation of complex structures to avoid mesh distortion. Furthermore, the optimization problem is effectively solved by combining the gradient optimization algorithm. Several numerical examples are presented to verify the accuracy of the method, and interesting structures such as the Miura-ori structure, switch and bionic structures are designed. The method can significantly reduce the optimization design variables, and the explicit optimization results can be used as the basis for the additive manufacturing of soft devices.