Fibers on the surface of thermo-responsive gels induce 3D shape changes

Using computational modeling, we pattern the outer layers of thin, thermo-responsive gels with elastic fibers and thereby design stable structures that could not be achieved with the fibers in the interior of the network. To perform these studies, we simulate the fiber-decorated gels with the gel lattice spring model (gLSM) and determine how the temperature, arrangement and number of the fibers control the bending and curvature of the thin films. We establish arrangements of the fiber on square- and rectangular-shaped gels that yield reversible, pronounced contraction and extension of the layer with changes in temperature. Hence, these composites provide useful actuation. Finally, we cut the gel into a cross-shaped sample to show that the modes of actuation and functionality of the material can be significantly expanded by tailoring not only the fiber placement, but also the initial geometry of the gel.