7.8 Smart Materials and Structures

Due to some properties which are close to those of biological materials, and their response to the environment, some chemicals, polymers and composites have more recently been considered as smart materials. The smart materials field is a new area of materials science and engineering and hence the number of concepts is not finally established. Its development is advancing based on conceptual and fundamental research in materials and technology of manufacturing [289].

The expression smart materials and structures is widely used to describe the unique marriage of materials science and structural engineering by using sensors (mostly based on optical fibres) and actuation control technology [287].

It is considered that the smart materials will have an important series of functions such as sensory, processor, executive functions, information transfer, energy transformation, etc. A great deal of smart materials work is still in the research stage. So far conductive (conjugated) polymers appear to be the largest area of growth but their manufacturing continues to be expensive [290]. Also the blending of non-covalent interactions with traditional polymer chemistry can lead to a novel class of smart (responsive) materials allowing a new access to high technology applications [291].

The field of smart materials and structures is emerging rapidly with technological innovations appearing in engineering materials, like sensors, actuators and image processing. Smart materials can be defined in several ways [292]:

• Materials functioning as both sensing and actuating.

• Materials which have multiple responses to one...