ABSTRACT In conventional piezoceramics, the coordinated change between the dielectric constant ( ε r ) and the piezoelectric charge constant ( d 33 ) usually limits the piezoelectric voltage constant g 33 ( g 33 = d 33 / ε r ), a critical figure of merit for piezoelectric sensors. In porous piezoceramics (PPCs), air as a secondary phase reduces ε r , whereas controlling 3‐dimensional (3D) pore structure through processing can enhance ceramic skeleton connectivity, thereby benefiting d 33 and enabling the decoupling of electrical parameters. In this work, we fabricate PPCs of PZT‐PZN‐PNN (PZNNT) via the gel‐casting method with varying solid contents. The 5‐vol% PZNNT 3D‐PPC realizes an 84.5% sharp reduction in ε r and a 55.2% retention of d 33 that synergistically elevates g 33 to 99.7 × 10 −3 Vm N −1 , which is 3.7 times that of dense ceramic. Experimental and simulation results confirm that the low stiffness and large deformations of porous materials enable both stress absorption and amplification, thereby enhancing the electromechanical conversion efficiency of piezoelectric materials. Ultimately, the fabricated 3D porous piezoceramic demonstrates exceptional electrical output and sensitivity, whereas its low density and acoustic impedance synergistically position it as a highly competitive candidate for hydrophone and sensor applications.
Xiaoying et al. (Sun,) studied this question.