Energy harvesting from sonic noises by phononic crystal fibers.

In this investigation, a phononic crystal-based fiber is proposed for energy harvesting application in metalworking factories. Phononic crystal plays the role of cladding in elastic fiber structure. Each of single-core fibers includes a tungsten hollow cylinder in central region which its internal radius is different in three single-core fibers. Incident waves with central frequency from 25 to 40 kHz of 1/3 octave band are confined in the core region of proposed elastic fibers and transmitted to desired distance. High confinement and transmission ability without significant longitudinal loss make this structure distinct from the other phononic crystals-based energy harvesters. By utilizing of a piezoelectric film at the end of fiber cores, mechanical energy is converted to electrical energy. As proposed elastic fibers confine the applied waves with high quality, the obtained output power is enhanced up to 800 times in comparison with the bare case. Maximum value of extinction ratio between all single core fibers is equal to - 23 dB. Also, longitudinal loss is almost equal to 0.9 dB/km.