Self-folding smart structure inspired by nature's heliotropism

Various plants are capable of comparably fast movements due to so called motor cells able of changing their internal pressure causing the flower head to rotate towards the sun. This principle, known as heliotropism, can be adapted by assembling an array of inflatable cells with highly flexible walls interconnected by micro pumps and valves to facilitate a pressure change between cells. Due to this internal pressure change, the volume of specific cells will vary causing the structure to deform and bend. By producing an array of a few cells thick but hundreds of cells long and wide, a plate that is able to change its shape can be created. The idea presented in this paper is to combine the folding capability of the developed smart plate with the origami principle of creating complex shapes from a single sheet of material without the need of irreversible cutting.