FUNCTIONAL AND SMART MATERIALS -Structural evolution and structure analysis

Smart systems and smart materials Smart structures are a new emerging materials system which combines contemporary materials science with information science. The smart system is composed of sensing, processing, actuating, feedback, self-diagnosing and self-recovering subsystems. The system uses the functional properties of advanced materials to achieve high performances with capabilities of recognition, discrimination, and adjustification in response to a change of its environment. Each component of this system must have functionality, and the entire system is integrated to perform a self-controlled smart action, similar to a living creature who can "think", make judgment and take actions. A smart system can be considered as a design philosophy that emphasizes predictivity, adaptivity and repetivity. A smart system/structure is defined to be a non-biological physical structure having the following attributes: (1) a definite purpose; (ii) means and imperative to achieve that purpose; and (iii) a biological pattern of functioning (Spillman et al., 1996). Smart materials are a subset of the smart system, i.e. smart structures at the microscopic or mesoscopic scales. Smart system is a non-biological structure which means that the system functions as a biological system rather than the pattern of functioning of a Turning machine. A smart material is a physical structure having (i) a definite purpose, (ii) means of imperative to achieve that purpose, and (iii) the pattern of functioning of a universal computer or Turning machine. Such a material will generally include at least one structural element, some means of sensing the environment and/or its own state, and some type of processing and adaptive control algorithm. Science and technology in the 21st century will rely heavily on the development of new materials that are expected to respond to the environmental changes and manifest their own functions according to the optimum conditions. The development of smart materials will undoubtedly be an essential task in many fields of science and technology such as information science, microelectronics, computer science, medical treatment, life science, energy, transportation, safety engineering and military technologies. Materials development in the future, therefore, should be directed toward creation of hyperfunctional materials which surpass even biological organ in some aspects. The current materials research is to develop various pathways that will lead the modern technology toward the smart system.