ABSTRACT
With the advancement in technologies, researches are widely been carried out to develop devices that meet the global energy crisis and environmental pollution. For the last two decades, the demand for wireless sensor devices, wearable and implantable electronic devices, high power density, and longer lifespan power sources 1 are increasing day by day. Energy harvesters (EHs) possess the high potential to be considered as a promising candidate for independent power sources utilized in low-power electronic devices. Energy harvesting can be considered as an alternative energy solution for batteries and thereby developing pollution-free systems. There are several technologies adopted for energy harvesting which includes harvesting from light, temperature, mechanical motion, and temperature gradients. 1 The mechanical EHs utilize vibration, kinetic energy, or deformations to be converted to electrical energy, and piezoelectric effect is a process in 140which mechanical energy is converted to electrical energy and vice versa. 1,2 Piezoelectric devices are rapidly increasing their demand due to its high efficiency for energy conversion, miniaturization, easy implementation, and high power output. 2,3 Thus, piezoelectric energy harvesters (PEHs) with favorable features like enhanced piezoelectric coefficient, figure of merit, electromechanical coupling factor, and flexibility have received the keen interest amongst the scientific community. 2,3 This chapter discusses the piezoelectric energy conversion principles, different piezoelectric materials both lead and lead-free systems, and piezoelectric EHs both in nanoscale and MEMS scale. This chapter also deals with the limitations and benefits; applications and possible improvements in piezoelectric energy-harvesting technologies.
