Tokyo Institute of Technology (Tokyo Tech) explains that organic, polymeric materials usually have low thermal conductivity and are not suitable for rapid heat dissipation of electric and electronic equipment. In order to improve its thermal conductivity, it has been considered effective to heat transfer through a covalent bond by ‘orientation processing’ in which molecules are aligned in the same direction, or to composite with an inorganic material.
Tokyo Tech is looking to form regularly assembled structures in a wide scale from nano to macro (so called hierarchical assembly), observed in the natural systems and the hierarchically assembled structures prepared in this way. This phenomenon, where molecules accumulate around the perimeter as an aqueous solution in which molecules dissolve (coffee ring effect), was utilised to assemble a filamentous virus for the film preparation.
As a result, the team say they discovered the thermal diffusivity at the edge of the film enhanced to a value comparable to that of inorganic glass, and that facilitates the utilisation of the hierarchically assembled biomacromolecule. This, they claim, will help future development of electric and electronic devices composed of not only viruses, but also various naturally derived molecules.
Until now, orientation processing and compositing with inorganic materials have been considered effective for the high thermal conductivity of organic polymeric materials. However, since this virus film can be prepared by evaporating an aqueous solution of a filamentous virus at room temperature, the team expects it to lead to a method for easily constructing heat dissipation materials under mild conditions without special operations.