High-power piezoelectric energy harvester produced using [0?0?1]-textured (Na,K)NbO3-based lead-free piezoceramics |
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Authors: | Sun-Woo Kim Seok-June Chae Dae-Su Kim Jong-Un Woo Eun-Ji Kim Su-Hwan Go Jae-Min Eum Hyung-Won Kang Seung Ho Han Sahn Nahm |
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Affiliation: | 1. Department of Materials Science and Engineering, Korea University, Seoul, Republic of Korea;2. Department of Nano Bio Information Technology, KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea;3. Electronic Convergence Materials & Device Research Center, Korea Electronics Technology Institute (KETI), Seongnam, Republic of Korea |
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Abstract: | High-power piezoelectric energy harvesters (PEHs) require piezoceramics with a large kp and d33 but small εT33/ε0 values. The 0 0 1]-textured 0.96(Na, K)(Nb1?xSbx)–0.04SrZrO3 piezoceramics (x = 0.025 and 0.045) exhibited the improved electromechanical coupling factor (kp) and piezoelectric charge constant (d33); however, the increase of dielectric constant (εT33/ε0) was not significant. Further, the textured piezoceramic with x = 0.045 shows the large d33 × g33 value of 21.5 pm2/N, where g33 is piezoelectric voltage constant, indicating that texturing is a good technique to fabricate the piezoceramics for PEH. The impedance curve of the PEH consisting of the metal substrate and textured piezoceramic shows a piezoelectric resonance peak at a low frequency, which is the same as the mechanical resonance frequency of the PEH. Hence, the PEH can be considered a piezoelectric material. The figure of merit of the PEH was determined using the mechanical quality and electromechanical coupling factor calculated from the impedance curve of the PEH. A large power output of 1.7 mW was obtained from the type-1 PEH at the resonance frequency produced using the textured thick film (x = 0.045). Hence, this PEH can be used as a permanent power source for microelectronic devices in the Internet of Things. |
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Keywords: | energy harvesting figure of merit lead-free ceramics piezoelectric materials/properties texture |
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