A Low-Cost Impedance Analyzer for Fault Detection in Piezoelectric Materials

Abstract

Piezoelectric devices are widely used in many industries in the application of sensors, actuators, energy harvesters, and piezoelectric transformers. For this reason, different testing techniques have evolved over the years to measure the properties of piezoelectric material during production and while in the application as per the required specification. While in production, these testing techniques ensure that the piezoelectric materials are defect-free, and in the application, they should have a life more or equal to the product lifetime. This testing becomes critical during applications such as structural health monitoring where piezoelectric materials are embedded or glued with the structures and cannot be removed or replaced. These testing techniques generally involve studying the impedance response of piezoelectric material to analyze the health of piezoelectric material which can be related to the device/application health. An impedance analyzer is one of the tools with the help of which one can determine the behavior of piezoelectric material by analyzing its internal impedance. Impedance analyzer has the property to convert complex electrical signals into wave frequency, and by these wave frequencies, one can determine whether the piezoelectric material is working well or not under different circumstances, how much the piezoelectric material has degraded over time, is the material is cracked or physically damaged. In this thesis, a complete layout, design, and fabricated low-cost impedance analyzer has been developed for testing and analyzing piezoelectric ceramic materials. The impedance data acquired is compared with the analytical calculations to detect physical damage, faults, and degradation over time. The main feature of this analyzer is cost effectiveness and its comparison with various highend impedance analyzers. The accuracies of 89% and 76% are achieved over the range of 10-100 kHz and 100 kHz to 215 kHz respectively. The goal is to develop a robust analyzer that can make tasks easier for the scientists, researchers, and manufacturers who are working on the fabrication, testing, and analysis of piezoelectric material and make the system IoT enabled to communicate with cloud for further smartness and real time defect detection by using complex algorithms.