A review on 3D printed piezoelectric energy harvesters: Materials, 3D printing techniques, and applications

The worldwide energy and environmental pollution crisis is caused partly by the rising usage of non-renewable energy sources. Researchers try to find alternative energy systems capable of harvesting energies present in the ambient environment. For more than two decades, piezoelectric energy harvesting devices have been investigated since they represent a viable alternative to traditional power sources for small and low-power electronic devices. The properties of piezoelectric materials and their manufacturing technique significantly impact the performance of a piezoelectric energy harvesting device. Lead zirconate titanate (PZT) is known as the most effective piezoelectric material. However, its rigidity and toxic lead component are major concerns. Due to its high flexibility and excellent piezoelectric capabilities, Poly(vinylidene fluoride) (PVDF), a lead-free piezoelectric material, was proposed as an alternative solution. In addition, in recent years, three-dimensional printing (3DP) techniques, particularly FDM, have received a lot of interest in the piezoelectric energy harvesting field. Moreover, research studies have shown that piezoelectric energy harvesting can be used for many applications, including robotics. This paper aims to provide an overview of current piezoelectric materials and 3DP technology used in the fabrication of piezoelectric energy harvesters (PEHs) and their novel applications.