Optimization of polarization direction on 3D printed 3-3 piezoelectric composites for sensing application

As a typical smart material, 3-3 piezoelectric composite has a wide application in the fields of ultrasonic transducer, underwater acoustic detection and so on. Direct ink writing has great advantages in preparing 3-3 composites because of its straight-forward process and accurate control of the composites structure. In this work, a water-based PZT slurry of 52.0 vol% solid content was prepared with high storage and loss modulus and shear thinning characteristics. PZT ceramic scaffolds with different porosity were realized by direct ink writing, and 3-3 piezoelectric composites were then prepared by compounding PZT scaffold with epoxy resin. Compared with the common Z-polarized samples, the Y-polarized samples show higher piezoelectric coefficients d33 and piezoelectric voltage coefficient g33. When PZT content of the 3-3 composite was 34.4 vol%, the Y-polarized sample showed the highest g33 of 81.65 mV m/ N, and the sensing sensitivity could reach 9.81 V/N. Structural configuration and design via direct writing process show great potential for tuning and optimizing the piezoelectric properties of piezocomposites.