The Lead Zirconate-titane(PZT) ceramic is known by its piezoelectric characteristic, but also by its stiffness. The use of a composite based on a polyurethane (PU) matrix charged by a piezoelectric material, enable to generate a large deformation of the material, therefore harvesting more energy. This new material will provide a competitive alternative and low cost manufacturing technology of autonomous systems (smart clothes, car seat, boat sail, flag …). A thin film of the PZT/PU composite was prepared using up to 80 vol. % of ceramic. Due to the dielectric nature of the PZT,inclusions of this one in a PU matrix raise the permittivity of the composite. For the most of industrial applications, the composite will not be used at room temperature, and as the energy harvested from this new materials have a direct relation with their permittivity we have made a study about the variation of the permittivity at different temperature and frequencies.
There is a large amount of thermal energy wasted during the driving cycle of all kinds of vehicles. In this paper, a pyroelectric harvester system, based on temperature change, is designed for low-powered sensors for a reliable Electronic/Electric architecture development of autonomous vehicles. For this proposed approach, three main elements are required: Pyroelectric energy harvest module, energy conversion module and power storage module. The energy harvest module includes a pyroelectric material, which captures the temperature of the braking system, and harvests the wasted heat energy during the contact process. In the energy conversion module, the temperature variation through the pyroelectric material generates electricity, given the cooling phenomena with the ambient air. The energy potentially available in the form of heat produced by the friction involved in braking was evaluated using finite element analysis on the Multiphysics software environment. Therefore, we present stimulations of disc heating and cooling during the braking process at different speeds. Moreover, the potential for energy recovery in multiple rolling conditions is discussed, such as the braking cycles and the effect of the material thickness, used in the conversion module. The proposed system has undergone simulation analysis, which shows that the system can generate a voltage of 10.8 V and a power of 7.0 mW for a cycle of one braking process and around 9.5 mW for a cycle containing two successive braking. This result illustrates the feasibility of energy-autonomous applications in low-power sensors for new vehicle generations.
The Barium Titanates are very promising materials ecologically, but still have poor piezoelectric properties compared to the Lead Zirconate Titanates. So in order to improve them, a substitution of the zirconium in our ceramic (BT) has been investigated by X-ray diffraction (XRD) and grain size distribution. After the preparation of the BZT powder in chemical way we have added a sintering aid (Li 2 O 3 -Bi 2 O 3 -CuO) and we have tried to study our massive ceramic. The X-ray diffraction, grain size distribution and scanning electron microscope of the BZT with LBCu show a better particles arrangement and density. In other hand we have noticed an important improvement of the piezoelectric properties (d 33 = 220 pC/N at 25°C) especially in comparison with other lead-free ceramics. These properties make BZT a lead-free high performance material for piezoelectric applications.
Recent trends in electromechanical conversion using alternative materials, have demonstrated the advantages of using piezoelectric composites for energy generation. There have been several papers on ceramic/polymer composites in which the fillers have high piezoelectric constant. Basically, the energy harvested depends on the proportion of the piezoelectric properties of composite. The fillers size within the composites is also an important criterion of the composites properties. Thus, in this paper 0–3 composites, made of lead zirconate titanate (PZT) ceramic powder and polyurethane (PU) were prepared. Different sizes of ceramic grains were used: grains with average size of 10 μm, size under 80 μm and size under 100 μm. Sizes of the PZT grains was determined according to the homogenization efficiency of the composite. Piezoelectric (piezoelectric coefficient d33) and dielectric properties (dielectric constant) were investigated. They have shown an interesting improvement with the increasing grains size up to 20 pC/N and 100, respectively. In order to understand the composite behavior on the microscopic scale, a simulation was carried out by mean of a finite element method (FEM) software. Finally, an estimation of the harvested voltage was modeled according to the grains size.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.