Structural health monitoring - Sensing skin application

By University of Eastern Finland

How does the sensing skin work? 

UEF’s sensing skin (developed in collaboration with North Carolina State University) is a distributed surface sensing system. In this technique, the surface of a solid structure is covered with a layer electrically conductive paint, and electrical imaging (more specifically, 2D electrical impedance tomography) is used for detecting temporal changes in the conductivity of this paint layer. These images, in turn, give rich information on the physical and chemical conditions of the structure: Sensing skin can be used for, e.g. imaging crack patterns on concrete surfaces, measuring 2D strain fields, detecting leaks of harmful chemical agents and sensing 2D temperature distributions on structure surfaces.

What is the purpose of the technology?

The purpose of this technology is the structural health monitoring of concrete (and possibly other solid) structures. In geo-energy operations, concrete structures are of great importance in securing the casings and other well structures; thus, our main emphasis is in the crack/flaw detection in concrete and measuring of strain fields to infer stresses subjected to concrete structures.

Video: 3D ECT of moisture flow in cement-based materials

Field testings

The technology has been tested first with numerical simulations, then with real data from experiments carried out in laboratories (UEF and North Carolina State University).

First field site tests were carried out in St. Gallen in November 2019.