Fabrication and electromechanical characterization of mullite ceramic fiber/thermoplastic polymer piezoelectric composites

Various types of sensors such as piezoelectric ceramics and strain gauges are widely used to monitor the damage of automobile components, buildings, and so on. Among these sensors, piezoelectric sensors have a high‐energy conversion efficiency, that is a high sensitivity. Therefore, we fabricated a mullite fiber‐reinforced resin sheet with piezoelectric particles (Piezo‐MFRS) and evaluated their sensor performance. Piezo‐MFRS was fabricated by the hand layup method—the polyamide resin was mixed with piezoelectric particles and infused into the mullite fiber fabric. After that, the piezo‐MFRS was polarized by a corona discharge. We investigated the relationship between the applied impact load or vibration load to the piezo‐MFRS and the generated voltage. The piezo‐MFRS induced an output voltage of 20 mV under a compressive stress of 4 MPa, and an output voltage amplitude of 2 mV due to bending vibration of amplitude 0.5 mm. Therefore, it seems that the piezo‐MFRS is suitable for use as a load sensor. Furthermore, we confirmed that the tensile properties of piezo‐MFRS were not reduced by the addition of piezoelectric particles. Consequently, it is likely that piezo‐MFRS is a promising material for a rugged piezoelectric sensor and opens the door to monitoring large structures.