Stretchable electronics

Stretchable electronics, also known as elastic electronics or elastic circuits, is a technology for building electronic circuits by depositing stretchable electronic devices and circuits onto stretchable substrates or embed them completely in a stretchable material such as silicones or polyurethanes. In the simplest case, stretchable electronics can be made by using the same components used for rigid printed circuit boards. One of the things that need to change is the substrate and the interconnections, being made stretchable, rather than flexible (see Flexible electronics) or rigid (Printed Circuit Boards). Typically, polymers are chosen as substrates or material to embed. When rigid components are deposited onto stretchable substrates, the interconnects will be subjected to high mechanical strain whenever the substrate is flexed. This is because, when bending the substrate, the outermost radius of the bend will stretch so that the relative spacing of each interconnect will effectively increase in line with the increasing length of the substrate. Stretchable electronics attempts biomimicry of human skin and flesh, in being stretchable, whilst retaining full functionality. The design space for products is opened up with stretchable electronics. 3D conformable circuits are now possible by the application of stretchable cyber-skins consisting of elastomeric carrier substrates populated with stretchable conductors and devices. Stretchable electronics, also known as elastic electronics or elastic circuits, is a technology for building electronic circuits by depositing stretchable electronic devices and circuits onto stretchable substrates or embed them completely in a stretchable material such as silicones or polyurethanes. In the simplest case, stretchable electronics can be made by using the same components used for rigid printed circuit boards. One of the things that need to change is the substrate and the interconnections, being made stretchable, rather than flexible (see Flexible electronics) or rigid (Printed Circuit Boards). Typically, polymers are chosen as substrates or material to embed. When rigid components are deposited onto stretchable substrates, the interconnects will be subjected to high mechanical strain whenever the substrate is flexed. This is because, when bending the substrate, the outermost radius of the bend will stretch so that the relative spacing of each interconnect will effectively increase in line with the increasing length of the substrate. Stretchable electronics attempts biomimicry of human skin and flesh, in being stretchable, whilst retaining full functionality. The design space for products is opened up with stretchable electronics. 3D conformable circuits are now possible by the application of stretchable cyber-skins consisting of elastomeric carrier substrates populated with stretchable conductors and devices. Stretchable electronics are sometimes called elastronics a new, emerging class of electronics, that is expected to enable a range of new applications: Some examples follow: Cyber skin for robotic devices, imparting a network of sensors on a fully conformable, stretchable cyber skin; in vivo implantable sponge-like electronics; and flesh-like devices with embedded electronic nervous systems. Stretchable energy storage devices Most commonly used stretchable energy storage device is based on active materials for double-layer supercapacitors are carbon-based materials such as single-walled carbon nanotubes (SWCNTs), due to their excellent electrical conductivity and high surface areas. The carbon-based materials are also natural choices for stretchable supercapacitors, with proper structural engineering to impart stretchability to the devices. Most recent study by Li et al. shows the fully functionality of the stretchable supercapacitor under dynamic charging and discharging, for the first time, which is composed of both elastic PDMS substrates, buckled SWCNTs macrofilm and elastomeric separators. Although achieving excellent cycling stability, however, the key drawback of this stretchable energy storage based on supercapacitor technology is the low specific capacitance and energy density and this can potentially be improved by the incorporation of redox materials, for example the SWNT/MnO2 electrode. Another approach to creating stretchable energy storage device is the use of Origami folding principle. The resulting origami battery achieves significant linear and areal deformability, large twistability and bendability. The strategy described here represents the fusion of the art of origami, materials science and functional energy storage devices, and could provide a paradigm shift for architecture and design of flexible and curvilinear electronics with exceptional mechanical characteristics and functionalities