Silicon Pillar Structure Assisted Three Dimensional Carbon Nanotube Assembly: Fabrications and Rational Surface Modifications

In this paper, we review the recent research progress on Si pillar assisted hierarchical three dimensional (3D) carbon nano-tube structures focusing mainly on the rational modification of the 3D network of single-walled carbon nanotube (3DNC) structures and its potential applications. Compared with conventional carbon nanotube (CNT) based microstructures which have been studied by other researchers, the 3DNC attract more attention because of its unique hierarchical structure which is comprised of interconnected CNTs between Si pillars. Functionalization of CNTs without destroying the hierarchical 3D structure of 3DNC is always a challenge. Physical and chemical vapor depositions, electrochemical depositions, polymer coating, and capillary force induced self-assembly have been applied for the surface modification of 3DNC. Those modified 3DNC structures have been applied to various research areas, like signal enhancement, microfluidic chips, energy storage, catalysis, and sensors, because of their unique hierarchical 3D structures. We also introduce some synthetic works on the capillary force induced wall-shaped CNT structures on pillar substrates.