Conductive films that are both stretchable and flexible could have applications in electronic devices1, 2, sensors3, 4, actuators5 and speakers6. A substantial amount of research has been carried out on conductive polymer composites7, metal electrode-integrated rubber substrates8, 9, 10 and materials based on carbon nanotubes and graphene1, 2, 11, 12, 13. Here we present highly conductive, printable and stretchable hybrid composites composed of micrometre-sized silver flakes and multiwalled carbon nanotubes decorated with self-assembled silver nanoparticles. The nanotubes were used as one-dimensional, flexible and conductive scaffolds to construct effective electrical networks among the silver flakes. The nanocomposites, which included polyvinylidenefluoride copolymer, were created with a hot-rolling technique, and the maximum conductivities of the hybrid silver–nanotube composites were 5,710 S cm−1 at 0% strain and 20 S cm−1 at 140% strain, at which point the film ruptured. Three-dimensional percolation theory reveals that Poisson's ratio for the composite is a key parameter in determining how the conductivity changes upon stretching.
At a glance
- A rubberlike stretchable active matrix using elastic conductors. Science 321, 1468–1472 (2008). et al.
- Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature 457, 706–710 (2009). et al.
- A large-area, flexible pressure sensor matrix with organic field-effect transistors for artificial skin applications. Proc. Natl Acad. Sci. USA 101, 9966–9970 (2004). et al.
- Scalable assembly method of vertically-suspended and stretched carbon nanotube network devices for nanoscale electro-mechanical sensing components. Nano Lett. 8, 4483–4487 (2008). et al.
- A large-area wireless power-transmission sheet using printed organic transistors and plastic MEMS switches. Nature Mater. 6, 413–417 (2007). et al.
- Flexible, stretchable, transparent carbon nanotube thin film loudspeakers. Nano Lett. 8, 4539–4545 (2008). et al.
- Highly stretchable and conductive polymer material made from poly(3,4-ethylenedioxythiophene) and polyurethane elastomers. Adv. Funct. Mater. 17, 3069–3073 (2007). , , &
- A stretchable form of single-crystal silicon for high-performance electronics on rubber substrates. Science 311, 208–212 (2006). , , &
- Controlled buckling of semiconductor nanoribbons for stretchable electronics. Nature Nanotech. 1, 201–207 (2006). et al.
- Stretchable and foldable silicon integrated circuits. Science 320, 507–511 (2008). et al.
- Stretchable active-matrix organic light-emitting diode display using printable elastic conductors. Nature Mater. 8, 494–499 (2009). et al.
- Elastomeric conductive composites based on carbon nanotube forests. Adv. Mater. 22, 2663–2667 (2010). et al.
- Stretchable, porous, and conductive energy textiles. Nano Lett. 10, 708–714 (2010). et al.
- XPS demonstration of π–π interaction between benzyl mercaptan and multiwalled carbon nanotubes and their use in the adhesion of Pt nanoparticles. Chem. Mater. 18, 5033–5038 (2006). , &
- Controllable deposition of Ag nanoparticles on carbon nanotubes as a catalyst for hydrazine oxidation. Carbon 46, 747–752 (2008). et al.
- Transparent conductive film fabrication using intercalating silver nanoparticles within carbon nanotube layers. J. Nanosci. Nanotech. (in the press). , , , &
- Nano-silver particles assembled on one-dimensional nanotube scaffolds for highly conductive printable silver/epoxy composites. J. Mater. Chem. 20, 3579–3582 (2010). , , , &
- High performance fully plastic actuator based on ionic-liquid-based bucky gel. Electrochim. Acta 53, 5555–5562 (2008). et al.
- Cycling performance of lithium metal polymer cells assembled with ionic liquid and poly(3-methyl thiophene)/carbon nanotube composite cathode. J. Power Sources 180, 591–596 (2008). , , , &
- Green chemical functionalization of single-walled carbon nanotubes in ionic liquids. J. Am. Chem. Soc. 127, 14867–14870 (2005). , &
- Conductivity of ionic liquids in mixtures. J. Mol. Liq. 123, 43–50 (2006). , , &
- Ionic conduction and ion diffusion in binary room-temperature ionic liquids composed of [emim][BF4] and LiBF4 . J. Phys. Chem. B. 108, 19527–19532 (2004). , , , &
- Silver-plated carbon nanotubes for silver/conducting polymer composites. Nanotechnology 19, 495602 (2008). et al.
- Percolation threshold of conducting polymer composites containing 3D randomly distributed graphite nanoplatelets. Comp. Sci. Tech. 67, 2114–2120 (2007). &
- 130–131 (McGraw-Hill, 2001). & Mechanical Engineering Design
- The effects of additives on the actuating performances of a dielectric elastomer actuator. Smart Mater. Struct. 18, 015006 (2009). et al.
- Stretchable interconnects for elastic electronic surfaces. Proc. IEEE 93, 1459–1467 (2005). , , , &
- Hot pressing technology to produce wear-resistant P/M structural materials with dispersed solid inclusions. Powder Metall. Met. Ceram. 44, 341–346 (2005). , , , &
- Mechanical behavior of powders during compaction in a mold with variable cross sections. Int. J. Powder Metall. Powder Tech. 18, 129–145 (1982). , &
- An investigation of powder compaction processes. Int. J. Powder Metall. 30, 385–398 (1994). , , &