Design and fabrication of a piezoelectric out-put evaluation system for sensitivity measurements of fibrous sensors and actuators

In last decades, using fibrous piezoelectric materials as energy harvesters and sensors attracted huge attention. Ductile behaviors and biocompatibility are the most beneficial characteristics of polymer-based materials, particularly poly vinylidene fluoride which is used for fabrication of wearable energy harvesters and sensors. Evaluation of piezoelectric properties, especially fiber and nanofiber piezo-polymers, is one of the most important inconveniences mode, particularly to quantify the sensitivity performance of fabricated devices, i.e. output voltage divided by the applied pressure. Conventional methods mostly are indirect, irrelevant and predominantly measure a related parameter instead of the main factor; they are also time consuming, expensive, constrained and have a high error rate. In this study, based on direct effect of piezoelectric, a novel universal system (PiezoTester) is presented to characterize piezoelectric properties and sensitivity of sensors and energy harvesters, especially flexible polymeric devices. This system was used to test three samples that are different in ZnO nanoparticle percentage in poly vinylidene fluoride/ZnO electrospun mats and its results compared by other measuring methods such as XRD, FTIR and differential scanning calorimeter as indirect methods and criterion piezoelectric method as a direct method to validate its performance. Promising evidence inferred PiezoTester could be used as a reliable system to evaluate piezoelectric properties of flexible energy harvesters and sensors as well as wearable gadget and smart textiles.