Piezo-electric energy harvesting (PEH) is a technology that converts mechanical energy into electrical energy using piezoelectric materials. These materials can generate an electrical charge when subjected to mechanical stress or pressure. This process is known as the piezoelectric effect. Piezoelectric materials can be made from a variety of materials such as ceramics, crystals, and polymers. Some common examples of piezoelectric materials include lead zirconate titanate (PZT), lithium niobate, and quartz. Vibration-based energy harvesting, which captures energy from ambient vibrations, such as those generated by traffic or machinery. Impact-based energy harvesting, which captures energy from impact loads, such as those generated by foot traffic or falling objects. Strain-based energy harvesting, which captures energy from deformation of the piezoelectric material, such as that generated by bending or twisting. Piezoelectric energy harvesting systems are being used in a wide range of applications, including wireless sensors, IoT devices, wearables, and other portable electronic devices. They are also being used in various industrial and infrastructure applications, such as in bridges and buildings to convert vibrations generated by wind and traffic into electricity. When piezoelectric materials are subjected to mechanical stress, an electrical potential will be generated. There are many products that contain this direct piezoelectric effect, such as strain sensors, gas lighters, microphones, and ultrasonic detectors.