DEVELOPMENT OF A GRAPHENE NANOCOMPOSITE-BASED SENSOR FOR STRUCTURAL HEALTH MONITORING (SHM)

J. USECHE; M.R. PAGNOLA; I. PIÑERES; H. DE AVILA; M.MOLINA; JORGE PEÑA CONSUEGRA

Cartagena de Indias

Workshop; first Latin American Workshop on Structural Health Monitoring (LATAM-SHM2023); 2023

International Center for Numerical Methods in Engineering CIMNE Congress Bureau - Campus Nord UPC Building C1 - Office C4 C/ Gran Capita, S/N 08034 Barcelona, Spain.-

In recent years, there has been a growing fascination with highly stretchable and sensitive flexible strain sensors. These sensors have garnered significant attention due to their remarkable capabilities in various domains. Primarily utilized for human motion monitoring, and transparent and wearable electronic systems, these sensors have also found relevance in diverse fields such as structural health monitoring (SHM). This paper presents a silly putty/graphene-based nanocomposite strain sensor for application in SHM. The nanocomposite was synthesized by the solution blending technique, mixing graphene and cross-linked polysilicon to create bulk G-Putty. In order to be used as a strain sensor, taking full advantage of its unique electrical properties, the bulk must convert into ink; the G-putty ink involves preparing a vial of G-putty bulk, adding chloroform, and subjecting it to a sonic bath for a given time. On the other hand, the silly putty/graphene system was obtained by depositing the nanocomposite in the form of ink onto a soft Polydimethylsiloxane (PDMS) matrix using the electrospinning technique at 25000 volts, was used for its low cost, high production rate, and quality. The electrical characterization was carried out using a Solartron 1260A impedance analyzer, the platform for the electrical measurements was specially designed to measure the properties of these nanocomposites, consisting of flat parallel steel electrodesin a Teflon structure with coaxial gold-tipped wires. Using Nyquist ́s plots, the electrical resistance values were determined, which allowed for the calculation of resistivity and electrical conductivity values. Finally, the curves of electrical resistance change as a strain function yielded average gauge factor (GF) values of approximately 1.8, and a stretchability of over 500% was achieved. All the data obtained from the sensor is extracted by using an Arduino Uno card that works as a data acquisition card, connected to the measurement system. This allows the resistance change at the sensor to be read and sent to the central computer system through a wireless or wired communication channel. In this way, the system has the ability to track and interpret the data obtained from the sensor.