Thermoformed tubular channels piezoelectrets exhibiting piezoelectric-magnetic behaviors were recently presented as Thermoformed Magnetic-Piezoelectrets (TMPs). This alternative sensor was suitable for detecting external magnetic fields from distant magnets. In this contribution, TMPs transducer was investigated as current sensor, where the magnetic field produced by an electrical current passing through a energized wire, mechanically stimulate the TMP and consequently disrupt the electrical charge equilibrium providing an proportional electrical signal. The charge variation was correlated with the magnetic field intensity providing a piezo-magnetic coefficient, similar to those noted in traditional piezoelectrets. It has been noticed that under certain conditions TMP could present coefficients up to 498 × 10^5 pC/T. From these results, it was concluded that such a polymer-based device is suitable for monitoring electrical currents in live wires, providing an interesting solution for non-invasive current transducers with a reduced footprint.

This integrated study presents a thorough investigation into a novel class of electrets known as Magneto-Piezoelectret Thermoformed (MPT) devices. The research focuses on evaluating capacitance, quality factor, and the impact of magnetic fields on these devices. Fabricated by fusing fluoroethylene propylene (FEP) films and integrating magnetic strips, the MPT devices exhibit both magnetostrictive and piezoelectric effects in response to external magnetic fields. The study encompasses the latest advancements in material synthesis, fabrication techniques, characterization methods, and potential device applications. Measurements conducted under various electric currents and frequencies revealed that higher capacitance values are associated with increased electric charge storage in MPT devices. The devices demonstrated exceptional quality factors, particularly in the MHz range, suggesting their potential as efficient electric charge storage devices. Further investigation focused on the influence of magnetic fields on the magneto-piezoelectric response of MPTs. Thermoformed piezoelectrets, featuring open tubular channels and an additional magnetic layer, were explored for their potential as sensors for detecting magnetic fields. While the magnetopiezoelectric response exhibited linearity in the presence of magnetic fields, a decrease in charge storage capacity was observed due to mechanical stress on the tubular channels. The MPTs displayed a maximum resistance of approximately 0.75 T against magnetic fields, reaching complete saturation at a magnetic field strength of 0.8 T. Beyond this point, the relationship between variables became nonlinear, resulting in a null magneto-piezoelectric response. This comprehensive study contributes to a deeper understanding of the capacitance, quality factor, and magnetic field influence on Magneto-Piezoelectret sensors. The insights gained from this research have significant implications for potential applications in advanced technologies that demand high-frequency operation and magnetic field detection.