  Due to the rapid growth in demand for power for sensing devices located in
remote locations, scientists' attention has been drawn to vibration energy
harvesting as an alternative to batteries. As a result of over two decades of
micro-scale vibration energy harvester research, the use of mechanical
nonlinearity in the dynamic behavior of the piezoelectric power generating
structures had been recognized as one of the promising solutions to the
challenges presented by chaotic, low-frequency vibration sources found in
common application environments. In this study, the design and performance of a
unique MEMS-scale nonlinear vibration energy harvester based on coupled
component structures and bi-stable states are investigated. The
coupled-components within the device consist of a main buckled beam bonded with
piezoelectric layers, a torsional rod, and two cantilever arms with tip masses
at their ends. These arms are connected to the main beam through the torsional
rod and are designed to help the main beam snap between its buckled stable
states when subjected to sufficient vibration loading. The fabrication of the
device will be discussed, including use of plasma-enhanced chemical vapor
deposition (PECVD) of silicon nitride under an alternating power field to
control compressive stress development within the main buckled beam. After
completing the fabrication process, the next step would be testing the device
under a variety of vibration loading conditions for its potential use as a
vibration energy harvester.
