Metamaterials allow the design of new functionality through the engineered control of light propagation, although broadband operation with these materials requires singularities in their refractive index. As a first example of a technique that uses a topological defect to achieve such behaviour in a real system, a omnidirectional metamaterial retroreflector is demonstrated.

Although sequential adsorption of dyes in TiO₂ electrodes is ideal for extending the range of light absorption in dye-sensitized solar cells, high-temperature processing has so far limited its application. A method for the selective positioning of organic dye molecules with different absorption ranges is now reported in a mesoporous inorganic oxide film.

For both successful and safe implementation of nanotechnology in biological applications the interactions between nanomaterials and biological systems need to be understood. The nano–bio interface is discussed from the perspective of the fundamental forces governing colloidal chemistry and the adaptations that occur at biological interfaces.