Patent ID: 7345331

Claim:
A ferroelectric capacitor circuit for sensing hydrogen gas, comprising: (a) a closed integrated circuit package; (b) a ferroelectric capacitor within the closed integrated circuit package, the ferroelectric capacitor comprising a bismuth oxide based ferroelectric layer between a first capacitor plate and a second capacitor plate, an outer perimeter of the bismuth oxide based ferroelectric layer being exposed within the closed integrated circuit package, the outer perimeter of the bismuth oxide based ferroelectric layer being able to absorb hydrogen gas that is within the closed integrated circuit package, absorbed hydrogen gas chemically reducing a portion of the bismuth oxide based ferroelectric layer into bismuth metal, the ferroelectric capacitor having a stored ferroelectric voltage, the stored ferroelectric voltage having a voltage strength; (c) an electrometer for measuring a decrease in the voltage strength of the stored ferroelectric voltage of the ferroelectric capacitor; and (d) a DC voltage source for storing the stored ferroelectric voltage in the ferroelectric capacitor.