Fabian O. Zayas Jimenez, Luis A. Chavez, and Yirong Lin
Energy systems like coal gasification unit or gas turbine waste a significant amount of thermal energy to the environment that can be harvested from pyroelectric devices. Wireless sensors can be completely self-powered and battery free by harvesting this wasted energy. Most sensors in energy systems are exposed to high temperature and harsh environment, therefore the use of materials that can withstand these conditions are desirable. The pyroelectric material used in this high temperature energy harvesting project is Lithium Niobate (LNB). LNB is used because of its high Curie temperature of 1142 ̊C, thus making it promising to be applicable for high temperature energy harvesting compared to other pyroelectric ceramics. In addition, LNB is a lead-free material perfect to avoid damage to the environment and human health. Pyroelectric materials have the potential to generate electrical power from temperature fluctuations. In this research, a custom testing setup was developed to create a controlled heating and cooling environment. The current and power output generated from the pyroelectric material at different temperature ranges was characterized. The energy harvested was characterized by varying the resistive electrical load applied to the sample until the highest power output was found. With a controlled temperature change in the range of 200 ̊C to 225 ̊C it was found that a single wafer of LNB (7.62cm diameter, 0.5 mm thickness) can generate a peak power of 232nW and a peak energy density of 102nWcm¯³ with an optimal resistance of 70Mꭥ.