text: Columnar structures have also been studied intensively in the context of nanotubes. Their physical or chemical properties can be altered by trapping identical particles inside them. These are usually done by self-assembling fullerenes such as C60, C70, or C78 into carbon nanotubes, but also boron nitride nanotubes
  Such structures also assemble when particles are coated on the surface of a spherocylinder as in the context of pharmaceutical research. Lazáro et al. examined the morphologies of virus capsid proteins self-assembled around metal nanorods. Drug particles were coated as densely as possible on a spherocylinder to provide the best medical treatment.
  Wu et al. built rods of the size of several microns. These microrods are created by densely packing silica colloidal particles inside cylindrical pores. By solidifying the assembled structures the microrods were imaged and examined using scanning electron microscopy (SEM).
  Columnar arrangements are also investigated as a possible candidate of optical metamaterials (i.e. materials with a negative refractive index) which find applications in super lenses or optical cloaking. Tanjeem et al. are constructing such a resonator by self-assembling nanospheres on the surface of the cylinder. The nanospheres are suspended in an SDS solution together with a cylinder of diameter , much larger than the diameter of the nanospheres  (). The nanospheres then stick to the surface of the cylinders by a depletion force.