Impact dynamics and polarization mechanism of BaxSr1−xTiO3 particles reinforced polydimethylsiloxane composites

Abstract Ba x Sr 1− x TiO 3 (BST) ceramics have excellent performance of electromechanical conversion, however, the application of BST ceramics in the field of sensing is restricted by the brittle fracture, electromechanical failure, and collateral damage of BST under impact. In this article, unpolarized BST particles reinforced polydimethylsiloxane (PDMS) composites‐BST/PDMS with excellent mechanical properties, flexibility and flexoelectric coefficient have been prepared. Experimental study on the dynamic mechanical behavior and polarization characteristics of BST/PDMS composites under different impact velocity, element ratio and content of BST are carried out. Furthermore, the three‐phase model have been developed, based on that, impact deformation, stress behavior and polarization response have been investigated. The results show that, the duration of elastic deformation stage increases with increasing of BST content, but maximum stress decreases; time‐history curves of polarization voltage are approximately a “sine” function distribution, polarization voltages of Ba 0.75 Sr 0.25 TiO 3 /PDMS are higher than that of Ba 0.25 Sr 0.75 TiO 3 /PDMS; flexoelectric coefficient increases with increasing of BST content, and μ zzzz is larger than that of μ xxzz and μ xzxz ; addition of BST particle leads to greater strain gradient, and increases the polarization voltage of PDMS matrix; electric field at the interface increases due to the dielectric effect, which improves the ability of charge migration, voltage difference of 20% Ba 0.75 Sr 0.25 TiO 3 /80% PDMS caused by interfacial potential is smaller (about 9.3%) compared with 10% Ba 0.75 Sr 0.25 TiO 3 /90% PDMS. This work is significant for the development of flexible intelligent sensing materials. Highlights The mechanical behavior and polarization characteristics of BST/PDMS are studied. The polarization voltages of BST/PDMS ( x = 0.75) are higher than BST/PDMS ( x = 0.25). The flexoelectric coefficient increases with increasing of BST content.