In this paper, we develop a multi-layer multi-functional electrical impedance tomography-based sensing skin. This sensing skin is made of two layers. The electrical conductivity of one layer changes due to cracking and the presence of chloride ions, while the electrical conductivity of the other layer changes only due to cracking. We monitor the local change in conductivity of each layer with Electrical Impedance Tomography (EIT). This sensing skin enables detection and differentiation of both cracking and the presence of chloride ions. We apply this sensing skin to concrete substrate. The results indicate that the developed technology can be potentially used for health monitoring of critical infrastructure systems where cracking and leakage of certain ions might be of concern.
doi: 10.12783/SHM2015/381