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 threedimensional network, as identifi ed by mechanical modelling. To demonstrate the applications of three-dimensional poly(dimethylsiloxane), we create a stretchable conductor obtained by fi lling 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 suffi cient for interconnects in light-emitting diode systems. Collectively, these concepts provide new design opportunities for stretchable electronics.

Mechanically Durable and Highly Stretchable Transistors Employing Carbon Nanotube Semiconductor and Electrodes

“…[ 17,23,35,36 ] Plastic materials, such as organic semiconductors and metal thin fi lms, often exhibit continuous plastic deformation with repeated strain cycles. [ 23,28,30,34,37 ] In contrast, networks of 1D materials accommodate strain by sliding and buckling of the individual elements.…”

Holographic patterning of high-performance on-chip 3D lithium-ion microbatteries

“…It is both highly scalable and compatible with microelectronic processing because it uses many of the same materials and procedure common in conventional photolithography. Although here a four-beam holographic strategy is used, which is not a standard lithographic process, holographic exposures have also been demonstrated using both prism and phase-mask methods that can be performed using a standard photolithographic process (25,26,38). Compared with conventional battery electrode fabrication methods (e.g., slurry tape-casting), which are difficult to scale to the millimeter size and below, the template-assisted electrodeposition provides a viable path for creating miniaturized electrodes with high-quality active materials conformally attached to 3D mesoporous current collectors.…”

From stretchable to reconfigurable inorganic electronics

“…Some examples include mercury, eutectic gallium-indium alloy (EGaIn), gallium-indium-tin alloy (Galinstan), and just recently, the biphasic Ga2Au alloy [88] . As liquids, these metals have gained significant interest because of their high electrical conductivity (1.0 × 10 6 S.m -1 for Hg and 3.4 × 10 6 S.m -1 for gallium-indium alloys) and extreme stretchability, > 600 %, without losing conductivity [89,90] . As an alternative to the toxic mercury-based stretchable conductors that have been heavily investigated in the past [91,92] , EGaIn and Galinstan have received more attention recently [93][94][95] .…”