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.