Coated nanofiller/polymer composite sensor network for guided-wave-based structural health monitoring

A method for forming a structural-strain sensor network on a surface of a structure, the sensor network comprising plural nanocomposite sensing elements dimensioned and located according to a pre-determined floor plan, all the sensing elements having a pre-determined thickness, the method comprising:

• obtaining a coating material used for forming the sensing elements, the coating material being a nanocomposite hybrid material under a semi-liquid state, wherein the nanocomposite hybrid material is a composite comprising nanofillers and a thermoplastic polymer;
• attaching a molding layer onto the surface, wherein the molding layer comprises plural openings dimensioned and located according to the floor plan, and the molding layer has a thickness same as the pre-determined thickness of all the sensing elements;
• after the molding layer is attached to the surface, filling the openings with the coating material;
• immobilizing the coating material that resides in the openings to form the sensing elements on the surface, so that an entirety of the sensing elements is collectively formed in two steps of filling the openings and immobilizing the coating material without a need to individually form each of the sensing elements;
• peeling off the molding layer from the surface after the sensing elements are formed;
• and
• forming electrical wires over the surface such that two opposite electrodes are formed on an individual sensing element and the two opposite electrodes are electrically accessible via two of the electrical wires, whereby variation of a resistance value of the individual sensing element, measurable through the aforesaid two of the electrical wires, corresponds to a strain experienced at a location of the surface on which the individual sensing element is located.