Three-dimensional nanonetworks for giant stretchability in dielectrics and conductors

Abstract

The realization of levels of stretchability that extend beyond intrinsic limits of bulk materials is of great importance to stretchable electronics. Here we report large-area, three-dimensional nano-architectures that achieve this outcome in materials that offer both insulating and conductive properties. For the elastomer poly(dimethylsiloxane), such geometries enhance the stretchability and fracture strain by ∼62% and ∼225% over the bulk, unstructured case. The underlying physics involves local rotations of narrow structural elements in the three-dimensional network, as identified by mechanical modelling. To demonstrate the applications of three-dimensional poly(dimethylsiloxane), we create a stretchable conductor obtained by filling the interstitial regions with liquid metal. This stretchable composite shows extremely high electrical conductivity (∼24,100 S cm-1) even at strains >200%, with good cyclic properties and with current-carrying capacities that are sufficient for interconnects in light-emitting diode systems. Collectively, these concepts provide new design opportunities for stretchable electronics. © 2012 Macmillan Publishers Limited. All rights reserved.