Preparation And Dynamic Strain Sensing Performance Research Of High Performance Ba(Ti_0.8Zr_0.2)O₃-0.5(Ba_0.7Ca_0.3)TiO₃ Based Piezoelectric Sensor

The monitoring of different stress,strain or other parameters can be achieved by the unique machine/electric conversion properties of piezoelectric material,the mechanical energy in the environment can be collected at the same time.Piezoelectric sensor applications and energy harvesting technology based on piezoelectric materials is very important for complex dynamic stress/strain monitoring and the development of self-powered electronic devices(such as wireless sensor networks).Lead-free piezoelectric material Ba(Ti0.8Zr0.2)O3-x(Ba0.7Ca0.3)TiO3(abbreviated as BZT-xBCT)can exhibit an excellent piezoelectric constant d33 about 620 pC/N.Here,we fabricate piezoelectric polymer composite material by synthesizing 0.5BZT-0.5BCT nanofibers via an electrospinning process,the performance of device was further improvd by doping the conductive phase in piezoelectric composite material.The piezoelectric sensors were fabricated based on piezoelectric composite material,their performance in energy harvesting and sensing were further explored.The main research contents include:(1)The synthesis of 0.5BZT-0.5BCT nanofibers via electrospining technique.The microscopic morphology and the piezoelectric,ferroelectric properties of the fibers were studied.Piezoelectric composite material was fabricated based on 0.5BZT-0.5BCT nanofibers,microstructure and composition of composites material were studied.(2)Preparation of sandwich structure piezoelectric sensor based on piezoelectric composite material.the effects of the composition ratio and the thickness of the piezoelectric layer on the electrical signal properties were studied in order to find the best preparation technology;The effect of MW-CNTs addition on the output of the generator is discussed;The effect of external load on the output performance,dynamic response and stability of the generator are studied.(3)Study on the sensing characteristics of piezoelectric sensor and its application in energy harvesting.The sensing characteristics of the sandwich structure piezoelectric sensor for the extrusion deformation and the vertical impact force were studied;prepare piezoelectric tensile strain sensor based on piezoelectric composite materials,the sensitivity,linearity,resolution and mechanical properties were studied to explore its application as a sensor.