Modeling of polyurethane/lead zirconate titanate composites for vibration energy harvesting

Abstract

Collecting the vibration energy existing in the surrounding environment and its transformation to a useful electrical energy in order to supply ultra-low power systems remains an emerging and promising technology. During the last decades, most of research efforts dealt with energy-harvesting technology using piezoelectric ceramics. However, those materials are stiff and limited in mechanical strain abilities. In addition, they lose their stiffness and piezoelectricity at high levels of mechanical strain. Thus, they are unsuitable for many applications in which low frequency and high strain level are required. However, electrostrictive polymers are lightweight, very flexible, have low manufacturing costs and are easy to mould into any desired shapes. These special properties led to them being considered as potential actuators. However, it is not well known that these materials also can be used for mechanical-to-electrical energy harvesting. In this research paper, electromechanical characterization of polymer/lead zirconate titanate composites was extended. The first part develops the analytical model predicting the energy harvested by polyurethane/PZT composites from electrical and mechanical properties of their constituent materials. Indeed, this model was based on the approach of representing the experimental setup with an equivalent electrical scheme. The second part focuses on the assessment of model performance by comparison between predicted and observed values. As a result, good agreements were observed between the two sets of data; in addition, the model could be used to optimize the choice of constituent materials. The last part concerns the contribution of both the electrostrictive effect and piezoelectric effect in electrical powers harvested by PU/PZT composites.

Piezoelectric Energy Harvesting Solutions: A Review

“…The performance of the piezoelectric energy harvesters is dependent on the transducer’s mechanical-electrical conversion efficiency [ 1 ]. The energy conversion efficiency for a piezoelectric transducer can be calculated using Equation (10) [ 48 ]: where is the electrical output power, defined in Equation (11), and is the mechanical input power (Equation (12)).…”

“…Piezoelectric energy harvesting systems are in general associated with three phases ( Figure 3 ) [ 1 , 50 ]: Mechanical—mechanical energy conversion: associated with the mechanical strength of the piezoelectric energy harvester under enormous stresses and the matching of mechanical impedance; Mechanical—electrical energy conversion: involves the electromechanical coupling factor of the piezoelectric energy harvester structure and piezoelectric coefficients; Electrical—electrical energy conversion: comprising electrical impedance matching …”

“…Rjafallah et al [ 1 ] modeled a PU-50%-vol%-PZT composite using the equivalent electric scheme presented in Figure 12 .…”

“…In recent decades, wireless technologies and microelectronics have led to the development of wearable devices, such as items of clothing and accessories, in which power is supplied either by batteries or energy harvesting devices [ 1 ]. In conjunction with these approaches is the concept of the Internet of Things (IoT), where wireless sensors networks are commonly used [ 2 ].…”

“…Therefore, mechanical energy is the most prevalent form of energy [ 9 ]. Using mechanical energy scavenging, sufficient power can be provided to ensure long-term autonomy for self-powered systems [ 1 ]. For example, around 10 mW can be harvested from the motion of the upper limbs, 1 mW can be obtained from a typing motion, breathing generates around 100 mW and, by walking, we generate up to 1 W [ 10 ].…”