Self-activated morphing carbon fiber composites via cyclic internal stresses

An innovative concept to exploit self-activated morphing composite materials is presented and demonstrated experimentally. In this design, shape changes of a carbon fiber composite are achieved by combining two key ingredients: fibers orientation and temperature-sensitive epoxy resin. When the fibers are properly oriented in each layer, internal stresses can be induced or gradually released by hardening or softening, respectively, the hosting epoxy resin. The epoxy resin stiffness is controlled with the help of internal heaters (e.g. the carbon fibers as demonstrated in this paper). The proposed mechanism results in a large scale and cyclic shape-changing capability which, together with the corresponding tunable stiffness, represent the fundamental features of morphing structural materials.