Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Nanocomposite Sensors of Indium Tin Oxide Nanowires in a PMMA Matrix for Structural Health Monitoring
Submission Author:
Eduardo Preto , SP
Co-Authors:
Eduardo Preto, Samuel da Silva, Marcelo Orlandi, Beatriz Ambrozini
Presenter: Eduardo Preto
doi://10.26678/ABCM.COBEM2023.COB2023-0093
Abstract
This paper proposes a new sensor that uses a nanocomposite composed of Indium Tin Oxide (ITO) nanowires embedded in a Poly(methyl methacrylate) (PMMA) matrix to detect the presence of damage in a structure. The nanocomposite has high transparency and conductivity. The proposed analysis measures the resistivity between terminals because the fibers network can change when damage modifies the nanowire's position. An electrical circuit converts the voltage applied to the sensor into resistivity. However, some weaknesses still need to be studied to enable a broader application of the sensor. This project aims to address two key points: defining the location of the damage and assessing the influence of temperature on the sensor. Experimental tests are conducted on an aluminum beam representing a structure, with damage-emulating cracks introduced on the sensor. The results demonstrate that the sensor's resistivity varies with the introduction of damage, and the resistivity change increases with increasing damage. The nanowires dispersed in the matrix undergo reorganization due to their difficulty in breaking, which changes the electric current path and may increase or decrease the resistivity. The new arrangement of the nanowires affects a large part of the sensor, but the intensity of the resistivity change tends to occur in the pairs of terminals close to the damage, indicating the damage location. All tests are conducted in a climatic chamber to ensure constant temperature and humidity. By varying the temperature, it is observed that the increase in temperature changes the resistivity due to the material characteristics. These initial tests need more reproducibility to ensure the wider use of this new sensor and to develop methods that standardize and facilitate their installation in structures.
Keywords
Nanocomposite sensors, ITO, PMMA matrix, resistivity, Structural Health Monitoring
