A Bending-Type Piezoelectric Energy Harvester with a Displacement-Amplifying Mechanism for Smart Highways

Abstract

Piezoelectric energy harvesting has gained attention owing to its effectiveness at harvesting electrical energy from various energy sources. Especially, with the increasing demand for smart highways, piezoelectric energy harvesting from road traffic has been increasingly studied. However, existing piezoelectric road-energy harvesters have limitations of low electrical output and low durability. A novel piezoelectric energy harvester was designed and fabricated to overcome these limitations. The proposed harvester had a maximum output power of 3.93 mW at a load resistance of 130 k Omega under an input displacement of 2.5 mm. The proposed harvester had 4.2 times more output power than the existing vibration-type road energy harvesters and was much less susceptible to destruction-in contrast to existing impact-type road-energy harvesters. The proposed road-energy harvester can be used as a power source for wireless sensor networks in smart highways.