Dynamic Approaches to Improve the Performance of Energy harvesters for Remote Sensing Applications

Energy harvesters (EHs) have gained significant attention as a potential source of renewable energy that can help in reducing CO2 emissions. Their potential can be attributed to their capability of converting normally wasted kinetic energy into useable electrical energy to power sensors located in remote areas, inaccessible locations, or harsh environments. Air conditioning (AC) units are one of the widely available sources of wasted vibration energy. In Saudi Arabia, the number of units can be estimated to be more than 25 million units. Hence, developing high-performance energy harvesters that utilize the vibration of AC units is desired to power indoor air quality sensors and structural health monitoring systems. However, the performance of energy harvesters is hindered by the low amplitude of the source vibration and the broad frequency spectrum. Here, we propose a novel design based on weakly coupled structural dynamic characteristics. The structures are designed to enable simultaneous activation of multiple modes in the nonlinear regime. This broadens the frequency response and increases the amplitude of the response. The first phase of this project consists of developing a finite element model to study different potential geometry and optimize the design parameters to obtain the desired performance metrics. The results will be verified using distributed / lumped parameters models. Then, the structures that have the desired performance metrics will be fabricated using additive manufacturing techniques such as 3D printing and coated with a piezoelectric film. The 3D printing techniques are selected due to their ease of fabrication and cost-effective manufacturing process. The piezoelectric film converts the mechanical vibrations into electrical energy. Different piezo materials will be explored to select the material with the highest charge density and simple coating techniques. In the second phase, the electrical readout circuit scheme will be designed and utilized to rectify and condition the generated electrical voltage and use it to power the targeted systems (e.g., sensors). The proposed study lays the foundation for developing novel energy harvesters that maximize the harvested power by employing nonlinear dynamics principles. Although the study targets harvesting the vibration energy of AC units, the same methodology can be utilized to maximize the harvested energy from a wide range of rotatiting machineries widely used in the oil and gas industry.