Effect of elastic modulus of cantilever beam on the performance of unimorph type piezoelectric energy harvester

Abstract

Piezoelectric energy harvesting is a technique that can utilize ambient vibration energy to generate useful electrical energy, which is promising for powering small-scale autonomous devices such as sensors for wearable, biomedical, and industrial applications. Typically, cantilever-type piezoelectric energy harvesters (PEHs) are operated under resonance condition to achieve the maximum output power at low frequency stimuli. Along with resonance matching, it is also necessary to optimize the PEH configuration with high electromechanical properties for the efficient energy conversion. The purpose of this study is to investigate the effect of the elastic modulus of the passive layer in the cantilever structured PEH on the electromechanical properties and thus harvesting performance. In this regard, two unimorph type PEHs having the identical geometry, piezoelectric properties, and proof mass but with different elastic modulus (55 GPa and 97 GPa) of Ti alloy-based passive layers were fabricated and their output performance was compared under the same acceleration amplitude excitation stimuli. The PEH with the smaller elastic modulus passive layer exhibited almost 53% improvement in the maximum power than that with the higher elastic modulus passive layer, which is attributed to a smaller mechanical damping ratio, higher quality factor, and larger vibration amplitude.

A Comparison Study of Fatigue Behavior of Hard and Soft Piezoelectric Single Crystal Macro-Fiber Composites for Vibration Energy Harvesting

“…The Mn-doped PMN-PZT and W-doped PMN-PZT SFCs having the dimensions of 28 (L) × 14 (W) × 0.2 (T) mm 3 were used as hard and soft piezoelectric materials, respectively (Figure 1a). The detailed manufacturing process of SFCs was reported in our previous study [32,33]. The SFCs were glued to a Ti alloy plate [60 (L) × 20 (W) × 0.25 (T) mm 3 ] using an epoxy resin (3M TM Scotch-Weld Epoxy Adhesive DP-460 EG) and then cured at 70 °C for 3 h. Further, the PEH was clamped with a rigid Bakelite holder and mounted on electromagnetic shaker for base excitation, as shown in Figure 1b.…”

“…Thus far, piezoelectric materials have been used as active materials in cantilever based PEHs in various forms including thin/thick ceramic patches (or wafers), polymers, active fiber composites (AFC), macro-fiber composites (MFC), or single crystal macro-fiber composites (SFC) [3,28], in which the MFC/SFC configuration offers high mechanical flexibility, stress-strain performance, endurance, and electromechanical properties. Although many reports are available on the energy harvesting performance of PEHs based on MFC/SFCs [29,30,31,32,33,34,35,36,37,38], the investigation on the reliability (fatigue behavior) of SFCs under continuous electromechanical cyclic loading over a long time is rare [39,40,41,42].…”

High performance of polycrystalline piezoelectric ceramic-based magneto-mechano-electric energy generators

“…Though the batteries are a logical solution, they suffer from the issues such as limited lifetime, maintenance, etc. Various autonomous powering paradigms using energy harvesting technology are the prime considerations for the solution [3][4][5][6][7][8][9]. Among the wasted energy sources, the ubiquitous stray magnetic field around the currentcarrying cables is one of the most promising sources [10,11].…”

Effect of single-side stroke limiter on cantilever-based piezoelectric energy harvesting from low frequency vibrations

“…However, such harvesters are not effective when there are small fluctuations in the ambient vibration frequency due to their relatively narrow operational bandwidth [12]. With regard to this issue, several approaches that allow frequency tuning have been proposed, such as monostable and bistable [13][14][15][16], multi-cantilever structures [13], passive and active stiffness-tuning technologies [17].…”