Conductivity enhancement in carbon nanocone adhesive by electric field induced formation of aligned assemblies.

We show how an alternating electric field can be used to assemble carbon nanocones (CNCs) and align these assemblies into microscopic wires in a commercial two-component adhesive. The wires form continuous pathways that may electrically connect the alignment electrodes, which leads to directional conductivity (∼10(-3) S/m) on a macroscopic scale. This procedure leads to conductivity enhancement of at least 2-3 orders of magnitude in the case where the CNC fraction (∼0.

Nanoparticle induced self-assembly.

Self-assembly has for the large part focused on the assembly of molecules without guidance or management from an outside source. However, self-assembly is in principle by no means limited to molecules or the nanoscale. A particularly interesting method to the self-assembly of micro- to millimetre sized components is the use of the 'magnetic hole' effect.

Aggregation dynamics of nonmagnetic particles in a ferrofluid.

Nonmagnetic microspheres confined in a ferrofluid layer are denoted by magnetic holes. They form aggregates due to dipolar interactions when an external magnetic field is exerted. Their cluster-cluster aggregation was studied for various magnetic fields using optical microscopy, both for small spheres of diameters, d=1.

Interaction model for magnetic holes in a ferrofluid layer.

Nonmagnetic spheres confined in a ferrofluid layer (magnetic holes) present dipolar interactions when an external magnetic field is exerted. The interaction potential of a microsphere pair is derived analytically, with precise care for the boundary conditions along the glass plates confining the system. Considering external fields consisting of a constant normal component and a high frequency rotating in-plane component, this interaction potential is averaged over time to exhibit the average interparticular forces acting when the imposed frequency exceeds the inverse of the viscous relaxation time of the system.