Reversible Nonlinear Energy Harvester Tuned by Tilting and Enhanced by Nonlinear Circuits

• Published in: IEEE/ASME transactions on mechatronics Vol. 21; no. 4; pp. 2174 - 2184
• Main Authors: Yang, Zhengbao, Zu, Jean, Xu, Zhuo
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bandwidth; Broad bandwidth; Couplings; Energy harvesting; Force; Hysteresis; Magnetic hysteresis; Magnetic resonance imaging; Mathematical analysis; multiple scales; Nonlinear dynamics; nonlinear vibration; Nonlinearity; perturbation method; piezoelectric; Rods; Softening; synchronized switch harvesting on inductor (SSHI); Vibration; Vibrations
• ISSN: 1083-4435; 1941-014X
• DOI: 10.1109/TMECH.2016.2530619

Nonlinear vibration is capable of effectively extending the frequency bandwidth of energy harvesters. Either hardening or softening nonlinearity has been used in various designs to achieve broad-bandwidth energy harvesting. In this paper, we propose a new method to achieve reversible hysteretic responses, i.e., both hardening and softening nonlinear responses, mechanically without additional magnetic interactions. This tunable nonlinearity endows energy harvesters with a great adaptability to environment. The proposed energy harvester is composed of a flexural center and two mass blocks, supported by a pair of elastic rods that are fixed on a vibration base. Different nonlinear responses are invoked by tilting the fixed-fixed elastic rods at different angles. A lumped-parameter model is developed to simulate the nonlinear electromechanical coupling system, and that is analytically solved by virtue of the high-order perturbation technique. The dynamic responses under different frequencies and accelerations are analytically characterized and compared well with the experimental data measured from a fabricated prototype. Furthermore, a nonlinear conditioning circuit (self-powered series synchronized switch harvesting on inductor) is constructed and tested with the proposed nonlinear energy harvester, with which the performance is enhanced about 200% for both resistive loads and capacitive loads.