Innovations & technologies

Quickly-grown graphite film blocks electromagnetic radiation

Graphite films can shield electronic devices from electromagnetic (EM) radiation, but current techniques for manufacturing them take several hours and require processing temperatures of around 3000°C. A team of researchers from the Shenyang National Laboratory for Materials Science at the Chinese Academy of Sciences has now demonstrated an alternative way of making high-quality graphite films in just a few seconds by quenching hot strips of nickel foil in ethanol. The growth rate for these films is more than two orders of magnitude higher than in existing methods, and the films’ electrical conductivity and mechanical strength are on par with those of films made using chemical vapour deposition (CVD).

All electronic devices produce some EM radiation. As devices become ever smaller and operate at higher and higher frequencies, the potential for electromagnetic interference (EMI) grows, and can adversely affect the performance of the device as well as that of nearby electronic systems.

Graphite, an allotrope of carbon built from layers of graphene held together by van der Waals forces, has a number of remarkable electrical, thermal and mechanical properties that make it an effective shield against EMI. However, it needs to be in the form of a very thin film for it to have a high electrical conductivity, which is important for practical EMI applications because it means the material can reflect and absorb EM waves as they interact with the charge carriers inside it.