Highly conductive, printable and stretchable composite films of carbon nanotubes and silver

Abstract

Conductive films that are both stretchable and flexible could have applications in electronic devices, sensors, actuators and speakers. A substantial amount of research has been carried out on conductive polymer composites, metal electrode-integrated rubber substrates and materials based on carbon nanotubes and graphene. 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.

Blending Electronics with the Human Body: A Pathway toward a Cybernetic Future

“…The hybrid film displayed unusual electromechanical properties with a conductivity at 5710 and 20 S cm −1 at 0% and 140% strains, respectively 225. Building on these results, a microscale paper‐cutting approach, based on a top‐down plasma etching technique, was developed to engineer even higher plasticity into carbon‐based nanocomposite polymers 432.…”

“…Perhaps the most promising approach to remedy the current situation is through the incorporation of multifunctional nanomaterials into polymers. Polymer materials that are stronger than steel, optically transparent, flexible, and highly conductive have been developed through the unification of nanomaterials and polymers 225, 427, 429, 430, 431…”

“…Existing bioelectronic devices primarily use metal electrodes such as Au, Pt, and Ag because of their suitable electrical properties, biocompatibility and corrosion resistance 221, 222, 223, 224, 225, 226. Especially, Au has been extensively used for bioelectronics due to its high ductility, good corrosion resistance, good biocompatibility, and long‐term operational stability.…”

Recent Progress in Electronic Skin

“…Conventional pressure‐sensitive rubber (PSR) sheets with carbon black are always integrated with transistors to create a pressure‐sensitive active matrix for mapping the pressure distribution, but these sheets also encounter low sensitivity and large hysteresis 23. Currently, many types of filler materials and elastomer matrixes, such as metallic particles,24 graphene,25 and carbon nanotubes26 have been investigated to improve mechanical and electrical properties. Recently, Bao and co‐workers demonstrated an ultra‐sensitive pressure sensor array with rapid response and a low‐pressure regime, i.e., as low as 1 Pa, using an elastic hollow‐sphere microstructured conductive polymer.…”

Biomimicking Topographic Elastomeric Petals (E‐Petals) for Omnidirectional Stretchable and Printable Electronics

“…The booming of research in ultraflexible, stretchable, and wearable electronics in the past decade has witnessed the remarkable development of advanced materials,1, 2, 3 structures,4, 5, 6, 7, 8, 9 and devices10, 11, 12, 13, 14, 15, 16, 17, 18, 19 that can function under large tensile strains (1%). In particular, the realization of highly conductive and stretchable metal interconnects, contacts, and electrodes are recognized as one critical milestone for these thin film devices 2, 13, 20, 21, 22, 23, 24.…”