Performance of Piezoelectric Power Generator in Environmental Conditions

Abstract

Piezoelectric power generators can be effective power suppliers for small devices by collecting energy from ambient vibration and converting it into electrical energy. Since such small devices are usually mobile, their operation environments can vary widely. For example, the conditions such as vibration frequency and temperature energy highly affect harvesting efficiency of piezoelectric power generators. If the ambient vibration frequency is away from the resonance frequency, there will be a decrease of output power. The ambient temperature can be a possible factor to change the resonance frequency of the power generating device since temperature influences material constants of the constituent components in a power generator such as dielectric constant, piezoelectric strain coefficient, and the stiffness Therefore, the effect of temperature on output power is studied. Since the common piezoelectric material is PZT and it is known that hard- or soft-type PZT exhibits different dependence of materials properties as a function of ambient temperature, this paper investigates the output power of the soft and hard PZTbased power generator depending on ambient temperature.