title: One hundred fold increase in current carrying capacity in a carbon nanotube-copper composite.
abstract: Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube-copper composite exhibiting similar conductivity (2.3-4.7 × 10(5) S cm(-1)) as copper (5.8 × 10(5) S cm(-1)), but with a 100-times higher ampacity (6 × 10(8) A cm(-2)). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (~2.0 eV) in carbon nanotube-copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters.
authors.affiliation: Technology Research Association for Single Wall Carbon Nanotubes, Central 5, 1-1-1 Higashi, Tsukuba 305-8565, Japan.
authors.forename: Chandramouli
authors.initials: C
authors.lastname: Subramaniam
authors.forename: Takeo
authors.initials: T
authors.lastname: Yamada
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Kobashi
authors.forename: Atsuko
authors.initials: A
authors.lastname: Sekiguchi
authors.forename: Don N
authors.initials: DN
authors.lastname: Futaba
authors.forename: Motoo
authors.initials: M
authors.lastname: Yumura
authors.forename: Kenji
authors.initials: K
authors.lastname: Hata