Vibration Energy Harvesting by Means of Piezoelectric Patches: Application to Aircrafts

Vibration energy harvesters in industrial applications usually take the form of cantilever oscillators covered by a layer of piezoelectric material and exploit the resonance phenomenon to improve the generated power. In many aeronautical applications, the installation of cantilever harvesters is not possible owing to the lack of room and/or safety and durability requirements. In these cases, strain piezoelectric harvesters can be adopted, which directly exploit the strain of a vibrating aeronautic component. In this research, a mathematical model of a vibrating slat is developed with the modal superposition approach and is coupled with the model of a piezo-electric patch directly bonded to the slat. The coupled model makes it possible to calculate the power generated by the strain harvester in the presence of the broad-band excitation typical of the aeronautic environment. The optimal position of the piezoelectric patch along the slat length is discussed in relation with the modes of vibration of the slat. Finally, the performance of the strain piezoelectric harvester is compared with the one of a cantilever harvester tuned to the frequency of the most excited slat mode.

Electrical Efficiency of SECE-based Interfaces for Piezoelectric Vibration Energy Harvesting

Piezoelectric energy harvesting (PEH) interfaces have been widely investigated during the last decades in order to maximize the harvested power. Among the energy extraction circuits proposed in the literature, some of the most effective ones consist of extracting the electric charges from the piezoelectric elements in a synchronous way with the vibrations and within a very short portion of the vibration period (SECE, SECPE, FTSECE, etc.). For these strategies, most previous studies take the electrical efficiency (i.e., the electrical losses between the energy extracted from the piezoelectric element and the energy which is finally transferred in a storage element) into account in an ad-hoc and case-by-case manner. In this brief, we propose a unified analysis that applies to model the electrical efficiency of these SECE-based strategies taking into account losses introduced by the electrical interface. We identify the main loss mechanisms by demonstrating that the electrical efficiency mainly varies with two parameters: the quality factor of the electrical interface and the voltage inversion ratio of the considered strategy. Measurements on the FTSECE strategy show that our model predicts the stored power with a good accuracy and allows a better optimization of the harvesting interface (up to 5.4 times more stored power at off-resonance frequencies, and 30% larger harvesting bandwidth).

Examination of Vibration Energy Harvesting in an Automobile

As observed in day-to-day life, driving on a bumpy road generates vibrational energy in an automobile which is then dissipated by the shock absorbers. But lately, as we progress into the energy-depleting, energy concern awake era, energy efficiency has been a serious concern within the automobile manufacturing industry since the production within the 1900s, researchers realized that the energy dissipated in traditional hydraulic shock absorbers is merit being recovered only within the middle of 1990s. Unlike traditional suspension systems which suppress the vibrations by dissipating the vibration energy into waste heat, the regenerative suspension with energy harvesting shock absorbers can convert the traditionally wasted energy into electricity. Several different techniques followed for the energy harvesting are listed and Two main devices namely rotary and linear electromagnetic generators are analyzed for comfort and handling, body acceleration with and without a generator, and also attempts is made to enunciate the importance of energy conservation techniques in an automobile.

Examination of Vibration Energy Harvesting in an Automobile

As observed in day-to-day life, driving on a bumpy road generates vibrational energy in an automobile which is then dissipated by the shock absorbers. But lately, as we progress into the energy-depleting, energy concern awake era, energy efficiency has been a serious concern within the automobile manufacturing industry since the production within the 1900s, researchers realized that the energy dissipated in traditional hydraulic shock absorbers is merit being recovered only within the middle of 1990s. Unlike traditional suspension systems which suppress the vibrations by dissipating the vibration energy into waste heat, the regenerative suspension with energy harvesting shock absorbers can convert the traditionally wasted energy into electricity. Several different techniques followed for the energy harvesting are listed and Two main devices namely rotary and linear electromagnetic generators are analyzed for comfort and handling, body acceleration with and without a generator, and also attempts is made to enunciate the importance of energy conservation techniques in an automobile.

Enhanced Energy Harvesting of Flexural Waves in Elastic Beams by Bending Mode of Graded Resonators

We show efficient elastic energy transfer and wave confinement through a graded array of resonators attached to an elastic beam. Experiments demonstrate that flexural resonators of increasing lengths allow to reduce wave scattering and to achieve the rainbow effect with local wavefield amplifications. We show that the definition of a monotonically decreasing distribution of the natural frequencies of the resonators along the wave propagation direction, is the preferable choice to increase the energy efficiency of the system. The proposed configuration is suitable for micro-fabrication, envisaging practical applications for micro-scale vibration energy harvesting.