Optical Vernier Effect-Based DC Piezoelectric Sensor for Low Voltage Applications.

In this paper, the deflection behaviour of a customized cantilever under low voltage conditions was experimentally studied and used as a sensor, taking advantage of their physical and optical properties. When voltage is applied, the bottom layer of the cantilever expands while the top layer does not, which causes the structure to bend due to strain mismatch. Intrinsic mechanical properties of the cantilever were characterized with an additional top layer of reflective material, to create a Fabry-Pérot structure that can respond to voltage changes. The importance of this sensor lies in their potential applications in various fields, such as renewable energy and batteries monitoring. Furthermore, depending on the application, the optical Vernier effect can increase and tune the sensor’s sensitivity. In summary, the significance of this optical Vernier effect-based direct-current sensor lie in their unique combination of piezoelectric and optical sensing capabilities using a high precision and adjustable interrogation method. Thus, allowing to measure changes in voltage below 100 mV in the Fabry-Pérot scenario and around 4 mV using the optical Vernier configuration.