Modeling of self-initialized electrostatic energy scavenger

With the expanding market of low-power wireless sensor nodes that would normally be deployed in great numbers, sometimes in harsh environment, the access to these nodes is problematic. This makes the process of maintaining and changing the batteries quite difficult and costly. The idea to convert vibration energy; existing in our everyday environment and especially in industrial plants, into electrical energy became very attractive. One promising technique, that is CMOS compatible, is based on MEMS electrostatic vibration energy harvesting. This technique suffers form a shortcoming problem which is the need for an initial charging voltage of the structure variable capacitor. In this context, the purpose of this work is to design a piezoelectric voltage generator integrable into the electrostatic structure to provide the necessary initial voltage. In that way the system will be self initialized and autonomous. This paper will focus on CMOS compatible piezoelectric transducers for initial DC voltage generation and their behavioral modeling using ELDO / VHDL-AMS.