ABSTRACT: Piezoelectric energy harvesting is a possible breakthrough to reduce the global issue of electronic waste as they can efficiently convert the ambient vibration to the electrical energy without any additional power. This work presents the design and development of a piezoelectric energy harvester that is capable of transforming vibration from ambient sources into electricity. It focuses on a magnetically plucked piezoelectric beam as an alternative to the mechanically induced harvesters, as the latter are subjected to wear and tear. A prototype comprising of a 40 mm PZT-5H piezoelectric beam with a permanent magnet mounted at one end of the beam, as well as a series of permanent magnets of same types attached on an eccentric rotor was developed along with a National Instruments® data acquisition device. Mean output voltages of 2.98 V, 1.76 V and 0.34 V were recorded when the eccentric rotors were slowly rotated at 8.4 rad/s with increasing distances of 5 mm, 7.5 mm and 10 mm respectively, between the magnets on the rotor and the beam. These results have proven that voltage could also be generated by magnetically plucking the piezoelectric beam, and by reducing the distance between magnets, the amount of voltage generated will be higher. The outcome of this work signifies the possibility for implementation of energy harvesters that are capable of powering electronic devices from hybrid kinetic motion, with a reduced risk of equipment fatigue.
ABSTRAK: Penjanaan tenaga melalui piezoelektrik adalah satu penemuan terbesar dalam mengurangkan isu global pengurusan sisa elektronik. Ini kerana ia berupaya mengubah getaran persekitaran kepada tenaga elektrik tanpa sebarang tambahan tenaga. Kajian ini berkenaan reka bentuk dan pembangunan penjana tenaga piezoelektrik yang mampu mengubah getaran persekitaran kepada elektrik. Fokus kajian adalah pada penjanaan tenaga secara magnetik dari bilah piezoelektrik sebagai alternatif kepada penjanaan mekanikal, kerana penjanaan tenaga secara mekanikal berisiko tinggi kepada kerosakan alat dalam jangkamasa panjang. Prototaip piezoelektrik PZT-5H yang berukuran 40 mm ini telah dilengkapi magnet kekal pada hujung bilah, serta satu siri magnet kekal jenis sama turut dipasang pada pemutar eksentrik bersama peranti pengambilan data National Instruments®. Secara purata, sebanyak 2.98 V, 1.76 V dan 0.34 V voltan output telah direkodkan ketika pemutar eksentrik berputar perlahan pada 8.4 rad/s dengan jarak tambahan antara magnet pemutar dan bilah piezoelektrik bersamaan 5 mm, 7.5 mm dan 10 mm, masing-masing. Keputusan menunjukkan tenaga dapat dihasilkan dengan cara pemacuan piezoelektrik secara magnetik, dan tenaga yang terhasil akan bertambah dengan pengurangan jarak antara magnet. Hasil kerja menunjukkan tenaga dapat dihasilkan daripada gerakan kinetik hibrid, dengan risiko rendah pada kerosakan alat.
Load Resistance Optimization of a Broadband Bistable Piezoelectric Energy Harvester for Primary Harmonic and Subharmonic Behaviors
