Energy generated through the pyroelectric effect using Macro-fiber Composites

Abstract

Waste energy harvesting is a method of generating small amounts of energy, usually through vibrations or thermal energy. Macro-fiber Composites (MFCs) have been employed in energy harvesting applications utilizing the piezoelectric effect, however, energy harvesting using the pyroelectric effect in MFCs has not been thoroughly explored. This paper takes strides in investigating the energy generated using the pyroelectric effect with P1 and P2 MFCs using two different oscillating temperature rates at 5°C/min and 10°C/min. Numerical temperature data along with analytical temperature functions were used to model the pyroelectric effect and the result was compared to experimental tests. Depending on the size of the MFC, type, resistor used, and the temperature rate, the energy generated varies from 0.4 to 24 µJ for the P1 MFC, and 8 to 459 µJ for the P2 MFC. The maximum specific power was also estimated analytically, numerically, and experimentally. A resistor sweep was performed using the numerical model to calculate the optimal resistance that would provide the most energy. The resistor was in the Gigaohm (GΩ) to Teraohm (TΩ) range for the specified temperature profiles. The required resistance to generate the maximum energy decreased as the temperature rate and the size of the MFC increased. This was validated with experiments conducted at varying resistances. Because this is energy generated from the ambient environment, pyroelectric harvesting can be used to power devices without cost to the source. This form of harvesting can be used in any place where there is a natural thermal cycle (i.e. due to weather or machine giving off thermal energy).