Smart Materials Group at the National Institute of Applied Science Recent Data and Trends

Abstract

During the last decade constant improvements have been made in materials and structures design and control. But now some performance objectives in particular in the field of the reliability cannot be achieved using classical technologies and require the use of the ‘smart materials concept’. Periodical maintenance NDT based inspections are today of a general acceptance for almost all complex technological structures. Nevertheless the idea that the integrated and continuous sensing techniques can optimize the operating conditions is now in progress. Different aspects of this evolution towards the desirable continuous health monitoring are discussed in relation with the smart materials concept through this non exhaustive review of some realisations or experiences. In the domain of sensitive materials, passive techniques such as Barkhausen effect, thermoelectric power, electrical impedance monitoring, acoustic emission, and active piezoelectric implant based methods, are briefly presented. Moreover, taking into account the growing demand in the field of actuators and artificial muscles for robotic and biomimetic devices, shape memory alloys and electroactive polymers are in progress. Finally the ‘self healing’ concept will be presented in the case of one ceramic-ceramic composite.