Combining dielectric elastomers with thin-film solar cells opens the prospect of self-powered, smart civil structures that adapt their shape autonomously in response to external stimuli. To explore the realm of stable equilibrium forms that these Dielectric Elastomer Minimum Energy (DEME) structures can take, we numerically simulated mechanically-coupled assemblies of DEME elements. In these models elastomeric membranes are first pre-stressed across triangular frames with low bending stiffness, and then two to eleven frames are connected along their edges in various configurations. Application of voltage across the membranes’ thickness is simulated by isotropic relaxation, which may be uniform or may differ between the membranes. We find that these configurations can assume a large variety of stable shapes, some of them quite surprising. We use the following approach. First, we use a finite difference method to represent the membrane of each triangular element with a triangular mesh. Second, we employ dynamic relaxation as a numerical analysis process to solve set of nonlinear equations based on Newton’s second law of motion. Briefly, the technique traces the motion of the dielectric membrane stretched over the bendable frame through time when loaded with pre-stress forces. Then we monitor the system until all out-of-balance forces have disappeared and the structure has reached a steady state. For some DEME structures we find more than one final shape. We validate our numerical results with physical model results and find that our simulated structures are in close agreement with those published. This projec is co-supervised by Prof. S. Wagner, Department of Electrical Engineering and Prof. C. Peters, Department of Civil and Environmental Engineering.
Publications:
Wagner S., Adriaenssens S., Huang T.Y., Jafferis N.T., Stone H.A., and Sturm J.C.(2012).‘Stretchable Electronics – From Passive 2D to Active 3D’. The 2012 International Conference On Flexible and Printed Electronics, Tokyo, Japan.
Huang T., Krupka M., Bagrianski S., , Wagner S. , Peters C., Adriaenssens S.(2011). ‘Shaping mechanically coupled assemblies of dielectric elastomer elements’.2011 Materials Research Society Fall Meeting, Boston, USA.
