Fabrication of robust carbon nanotube microstructures by elastocapillary densification

Carbon nanotubes (CNTs) have been studied extensively because of their outstanding electrical, mechanical and thermal properties. A common way to integrate CNTs in microsystems is to “grow” them from a catalyst layer using Chemical Vapour Deposition (CVD) [1]. The shape of the microstructures is controlled by patterning the thin catalyst layer which agglomerates to form catalyst nanoparticles. This method is particularly interesting for fabricating high aspect ratio microstructures, as the CNTs selforganize into a vertically aligned forest. Although this process is well established, the resulting CNT density per area is low, and as a result, the bulk properties of these structures are far below those of individual CNTs. Therefore, methods have been developed to increase the CNT density after growth. This research focuses on the characterisation of a densification based on capillary self-assembly. Figures 1 and 2 illustrate the CNT structures investigated in this research before and after the densification process respectively.