Smart materials and electro-mechanical impedance technique: A review

Abstract

Smart materials are catalyzed by a technological revolution that will explode several emerging technologies viz., material science, neural network, artificial intelligence, nanotechnology and biotechnology etc. These smart materials are now used in aerospace, mechanical and civil industries for the development and monitoring. The several types of smart materials are available such as PZT patches, optical fibers, piezo-polymers, shape memory alloys, magnetostrictive, shape memory polymers, bi-component fibers, self-healing materials and electro-rheological fluid, respectively. The Electro-Mechanical Impedance (EMI) technique is a local technique, which is based on smart materials. EMI technique is applied in the different fields of engineering to evaluate several parameters of the materials or structures. Moreover, this technique is used to measure cracks in steel as well as in concrete, corrosion of reinforcement, loosening of the bolt, strength gain, hydration of cement and debonding phenomenon etc. The conductance and susceptance signature is used for the determination of the presence of damage. The change in conductance signature from the baseline signature indicates the presence of damage/crack in the materials or structures. The review paper is focused on smart materials and their compatibility related to structures. The formulations concerning the EMI technique for the measure of structural impedance and electro-mechanical admittance were also considered. Furthermore, the smart materials based EMI technique and their appropriateness have been covered. Therefore, the application of smart materials in the field of engineering and industries is to provide new research directions.