Trafficking of molecules both into and out of a cell is a normal activity necessary for cell survival. Cells have evolved elaborate strategies for these transport processes while ensuring the integrity of the cell membrane. Some of these transport processes are thermodynamically driven, whereas others involve active transport mechanisms. Nanomedical design attempts to use the naturally occurring transport mechanisms to bring drugs into single cells.

Certain types of multi-component configuration, while not constituting conventional composite materials, can nevertheless be treated using the approaches and methodologies of composite theory. These include layered systems, particularly the simplest one of a (planar) substrate with a coating (‘deposit’) on one face. This is effectively a real version of the ‘slab model’ that is commonly used to predict composite properties such as stiffness, conductivity, etc. Such property prediction is, of course, valid for a substrate/coating system, although often of limited interest. However, the slab model can be extended in directions that are potentially more useful for coatings. In particular, the creation of curvature, which has only been touched on so far, in the context of (asymmetrical) laminates, can be predicted and utilised (for example to measure residual stresses in coatings). A central concept here concerns the misfit strain, which is used in earlier parts of the book (particularly as it relates to the Eshelby method).