Energy conversion mechanisms of a seesaw-type energy harvester

Abstract

Vibration energy harvesters with bistable characteristics, which can convert mechanical energy to electric energy, typically are cantilever beams with magnetic repulsion. In group to enhance its low-frequency performance, a seesaw-type approach has been proposed, which can make the structure overcome the potential barrier more easily. In this paper, we establish electromechanical coupling equations of the whole system, and prove that internal beam delivers mechanical energy to primary beam based on time-domain analysis. Meanwhile, frequency-domain analysis and solutions are conducted to investigate dynamical and electrical behaviours of the system based on the adjustment of different parameters. We find both mechanical and electrical responses are enhanced gradually with the decrease of relative damping coefficient within the bounds of the discussion. And maximum response amplitude can be increased by a factor of 11.3 just by adjusting the position of the internal beam. Furthermore, the length of internal beam can affect responses of the system visibly and regularly, and maximum response amplitude remains unchanged when changing the length of internal beam from 80 mm to 100 mm. All of these suggest that the mechanisms of seesaw-type energy harvester will provide guidance to design more appropriate structure depending on different applications.

Ferroelectret Polypropylene Foam-Based Piezoelectric Energy Harvester for Different Seismic Mass Conditions

“…The four main energy conversion mechanisms used for vibration-based energy harvesting are electromagnetic, electrostatic, piezoelectric, and triboelectric. The literature review shows certain shortcomings of electromagnetic energy harvesters, because of the use of permanent magnets to produce power from induced current in magnetic fields, the size of the harvester is comparatively bigger and hence there are problems of mechanical complexity in this mechanism [16,17]. In the electrostatic and triboelectric mechanism, it is hard to ensure continuous and secure production of energy, so this mechanism is limited to only a few applications due to its low current [18][19][20].…”

“…Also, for device sizes less than 1 cm 3 , piezoelectric mechanism shows higher energy conversion capacity compared to electromagnetic harvesters [5,21]. A thorough literature review suggests that there are far more advantages in piezoelectric-based vibration energy harvesters (PVEH) compared to their other counterparts, mainly because of the simple architectures and bigger energy density along with the additional features of ease in the scalability of piezoelectric and ferroelectret material in micro and nanoscale devices [14][15][16].…”