@inproceedings{b0c1b790298f4776a38e763e445ac95f,
title = "A novel miniature thermomagnetic energy harvester",
abstract = "Nowadays, thermal-energy-harvesting is an important research topic for powering wireless sensors. Among numerous thermal-energy-harvesting approaches, some researchers demonstrated novel thermomagnetic-energy harvesters to convert a thermal-energy from an ambient temperature-difference to an electrical-output to power the sensors. However, the harvesters are too bulky to be integrated with the sensors embedded in tiny mechanical-structures for some structuralhealth- monitoring applications. Therefore, miniaturized harvesters are needed. Hence, we demonstrate a miniature thermomagnetic-energy harvester. The harvester consists of CuBe-beams, PZT-piezoelectric-sheet, Gd-soft-magnet, NdFeB-hard-magnet, and mechanical-frame. The piezoelectric-sheet and soft-magnet is bounded at fixed-end and freeend of the beams, respectively. The mechanical-frame assembles the beams and hard-magnet. The length× width×thickness of the harvester is 2.5cm×1.7cm×1.5cm. According to this, our harvester is 20-times smaller than the other harvesters. In the initial-state of the energy-harvesting, the beams' free-end is near the cold-side. Thus, the soft-magnet is cooled lower than its curie temperature (Tc) and consequently changed from paramagnetic to ferromagnetic. Therefore, a magnetic-attractive force is produced between the soft-magnet and hard-magnet. Consequently, the beams/soft-magnet are down-pulled toward the hard-magnet fixed on the hot-side. The soft-magnet closing to the hot-side is heated higher than its Tc and subsequently changed to paramagnetic. Consequently, the magnetic-force is eliminated thus the beams are rebounded to the initial-state. Hence, when the harvester is under a temperature-difference, the beams' pulling-down/back process is cyclic. Due to the piezoelectric effect, the piezoelectric-sheet fixed on the beams continuously produces voltage-response. Under the temperature-difference of 29°C, the voltage-response of the harvester is 30.4 mV with an oscillating-frequency of 0.098 Hz.",
keywords = "Energy Harvester, Magnetic, Piezoelectric, Power Generator, Thermal",
author = "Chen, {Chin Chung} and Tien-Kan Chung and Cheng, {Chi Cheng} and Tseng, {Chia Yuan}",
year = "2014",
month = jan,
day = "1",
doi = "10.1117/12.2045294",
language = "English",
isbn = "9780819499837",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
booktitle = "Active and Passive Smart Structures and Integrated Systems 2014",
address = "United States",
note = "null ; Conference date: 10-03-2014 Through 13-03-2014",
}