Lead zirconate titanate aerogel piezoelectric composite designed with a biomimetic shell structure for underwater acoustic transducers

In this study, we used lead zirconate titanate (PZT) aerogels prepared by a solvothermal assisted sol-gel method as raw materials to synthesize PZT aerogel/PVDF composite coatings and PZT aerogel sintered sheets through natural annealing and PVDF composite and hot pressing, respectively, and then combined them with the design principle of a biomimetic shell structure to prepare an alternate coating/sheet structured PZT aerogel piezoelectric composite with natural distinguished mechanical properties. It had excellent piezoelectric properties with a piezoelectric coefficient d 33 of 435.15 pC N −1 and d 31 of −144.55 pC N −1 , excellent electromechanical coupling properties with a planar electromechanical coupling coefficient of 60.14%, low dielectric loss of 0.76% at 40 Hz and low density of 3.04 g cm −3 . When used as the piezoelectric material in underwater acoustic transducers (UATs), compared with all kinds of piezoelectric ceramics, it achieved higher piezoelectric and comprehensive mechanical properties, lower dielectric loss, lower density, and electromechanical coupling properties similar to that of Pb-containing piezoelectric ceramics, thus showing extremely promising application prospects in UATs. Combining 5-layer PZT aerogel/PVDF composite coatings and PZT aerogel sintered sheets based on the design of bionic shell structure, the PZT aerogel piezoelectric composite with natural excellent mechanical properties has been successfully prepared.