Dimensionless analysis of optimization of piezoelectric vibration energy harvester

Conversion of vibration energy in a structure, machine or vehicle into electric energy will improve reliability, comfort and energy utilisation efficiency, and can potentially reduce the amplitude of vibration and associated damaging effects. An analytical approach is proposed in combination of frequency analysis and time domain simulation. The main advantage of the approach is its capability to predict harvested resonant power and energy harvesting efficiencies of mechanical systems with built-in piezoelectric material, from a resonant frequency, mechanical damping, external load resistance and piezoelectric material properties regardless of the system size. The approach allows for prediction of output voltage and harvested resonant power from measured field vibration acceleration data. It allows for a parameter study and optimization of piezoelectric vibration energy harvesters. The dimensionless harvested resonant power and energy harvesting efficiency formula developed from this paper are useful for performance evaluation of the vibration energy harvesters ranging from macro to micro scales, even to nano scales. Potential industrial applications would be in ambient vibration energy harvesting analysis for machines or structure systems with built-in piezoelectric material. These systems may include engine torsion vibration absorbers (engine harmonic balancer), vehicle chassis suspension/mounting systems, vehicle power-train suspension/mounting systems, wheels and tyres or vehicle body panels. The harvested electric energy is expected to be used to power electronic devices, self-sustaining microand nano-scale sensors, or remote sensing systems including automotive electronics, sensors or wireless sensor nodes.