Recently, energy harvesting technology is increasing due to the fossil fuel shortages. Energy harvesting is generating electrical energy from wasted energies as sunlight, wind, waves, pressure, and vibration etc. Energy harvesting is one of the alternatives of fossil fuel. One of the energy harvesting technologies, the piezoelectric energy harvesting has been actively studied. Piezoelectric generating uses a positive piezoelectric effect which produces electrical energy when mechanical vibration is applied to the piezoelectric device. Piezoelectric energy harvesting has an advantage in that it is relatively not affected by weather, area and place. Also, stable and sustainable energy generation is possible. However, the output power is relatively low, so in this paper, newly designed honeycomb shaped piezoelectric energy harvesting device for increasing a generating efficiency. The output characteristics of the piezoelectric harvesting device were analyzed according to the change of parameters by using the finite element method analysis program. One model which has high output voltage was selected and a prototype of the honeycomb shaped piezoelectric harvesting device was fabricated. Experimental results from the fabricated device were compared to the analyzed results. After the AC-DC converting, the power of one honeycomb shaped piezoelectric energy harvesting device was measured 2.3[mW] at road resistance 5.1[KΩ]. And output power was increased the number of harvesting device when piezoelectric energy harvesting device were connected in series and parallel.

Eco-friendly (Na, K) Nb03 (NKN)-based piezoelectric ceramic materials were fabricated by conventional ceramic method for shear mode piezoelectric energy harvesting application. NKN-LiTaO3 (LT) based compositions were adopted for the high d15xg15 which is proportional to harvested energy density. The composition 0.935(Na0.535K0.485) NbO3-0.065LiTaO3 was found to be lie on the boundary of tetragonal and orthorhombic phases. With reducing Ta content, the dielectric constant decreased gradually while maintaining high d15, which resulted in increased d15xg15, The composition 0.935(Nao0.535K0.485)) NbO-0.065Li (Nb0.990Ta0.0010) O3 was found to possess excellent piezoelectric and electromechanical properties (d15sxg15 =29 pm2/N, d13 417pC/N, k15= 0.55), and high curie temperature (T 455t).