Nonlinear effects in electrostatic vibration energy harvesters: Current progress and perspectives

In this review paper, we discuss the principles of electrostatic (capacitive) vibration energy harvesters and nonlinear techniques that can be applied to improve the performance of harvesters. Electrostatic vibration energy harvesters are devices that contain mechanical resonators driven by ambient vibrations and coupled with conditioning electronic circuits through a capacitive transducer. While the devices can be fabricated using MEMS technology and miniaturised, internal and external nonlinearity and complexity can lead to irregular behavior and impede the analysis of the devices. In this review we give an overview of the capacitive conversion mechanisms, discuss the basic triangular energy conversion cycle in detail and survey the nonlinear techniques that can be employed in these systems.