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We propose a smart pen piezoelectric energy harvester (SP-PEH) that simultaneously produces energy in both d31 and d33 modes during writing. Two piezoelectric devices were installed in SP-PEH, a cantilever type device and an impact type device. With preliminary Fast Fourier Transform analysis on the writing conditions, power generation tests were conducted. For cantilever type, the harvester generated instantaneous maximum power of 1.5 μW (3 MΩ) at a writing frequency of 3 Hz (most frequent value during actual writing) and a writing length of 12.5 mm. For impact type, it generated 2.6 μW at a load resistance of 5 MΩ. With those power generations, the stored energy in the two capacitors were 1 μJ (47 μF, cantilever type) and 0.05 μJ (220 μF, impact type) separately for 10 s, and a total energy of 3.1 μJ (about 3 times higher than sum of two types) was stored in an actual writing test because of movement in all directions rather than just a single direction. The proposed device successfully turned on a ZigBee wireless sensor after 10 s, which confirmed the possibility of the battery-less smart pen that harvests energy and collects and transmits environmental and biological data from writing.

To meet the increasing demand for electric vehicles, this paper presents a novel concept to enhance the energy generation performance of piezoelectric energy harvesters used as charging stations on roads. A lever-type piezoelectric energy harvester with a deformation-guiding mechanism was designed and fabricated to overcome the existing limitations of low electrical output and low durability of piezoelectricity under extremely low road displacement conditions of 1 mm. The proposed harvester achieved a maximum output power of 60.3 mW at a load resistance of 50 kΩ under an input displacement of 1 mm. Thus, the module’s electrical performance was significantly higher than that obtained in previous similar studies. The proposed harvester had 467% higher output power than the previously proposed vibration type road energy harvester. For the energy storage test, a 0.08 F supercapacitor was charged up to 5.09 V (1 J) in 170 min. The results prove that the energy generated by the proposed harvester can be potentially used as a power source for electric vehicles on smart roads beyond the power supply of various sensor systems on the road.