Experimental Study of the Effect of Corona Poling Parameters on Additive Manufactured Pyroelectric PVDF-TrFE Sensors

After the discovery of piezo- and pyroelectricity in Polyvinylidene Fluoride (PVDF) and its copolymer with trifluoroethylene (PVDF-TrFE), numerous research initiated on their applications in sensing and actuating. The rise of additive manufacturing has resulted in the development of sensors and actuators for a wide range of fields, such as medical devices and MEMS. As a main step in making piezo- and pyroelectric sensors, electrical poling has not been thoroughly studied for additive manufactured sensors. In this study, we investigated the effect of corona poling parameters (i.e., voltage, duration, and distance between the electrodes) on additive manufactured PVDF-TrFE via Fused Deposition Modeling (FDM) method. As a result, we concluded that the print quality has significant impact on the poling process. For the samples that we manufactured it had been found that the maximum poling voltage that we were able to apply without creating electric discharge was 20 kV at 20 mm and 25 kV at 40 mm distance from the energized needle electrode to the sample. The piezoelectric and pyroelectric responses reaches a plateau after 10 min poling time. We utilized the pyroelectric response of the samples as a surrogate parameter to estimate the poling process efficacy. The maximum open circuit pyroelectric response of 60 mV peak-to-peak was observed for the samples poled at 25 kV for 10 minutes. This voltage is sufficient to power small electronic devices and charge batteries after use of energy harvester regulators.