ELECTRET-BASED ENERGY HARVESTING FROM VIBRATION

Tire pressure monitoring system (TPMS) has become a standard safety feature for
modem automobiles. It monitors the tire pressure of the equipped vehicles wirelessly,
to ensure safety of its driver and passengers. Obviously, such wireless device require
a power supply to function and battery has been the source of power. An energy
harvesting is becoming popular as an alternative power source for such application.
Among the renewable energy sources present, vibration energy is the most versatile
and ubiquitously available in the target environment. To convert vibration into
electrical, an electrostatic transduction mechanism is adopted, due to ease of
integration into the micro-system. However, electrostatic energy harvester requires
additional charge pump to function. To overcome the drawback, an electret-based
vibration energy harvesting device ( e VEH) is developed. This thesis presents new
techniques to develop the electret-based energy harvester device; the electrode
geometry, the variable capacitor topology and the electret material.