Temperature Effects on Resonance Behaviors of a Piezoelectric Transducer

Piezoelectric transducers are devices to cover energies between mechanical and electrical for sensing, actuation and energy harvesting, especially to gather mechanical energy from the surroundings and convert it into electrical energy using their electromechanical coupling capability. Among the numerous significant initiatives of energy conversion analysis, little consideration has been devoted to studying the impact of the environment on the effectiveness of energy conversion for piezoelectric transducers, particularly when the operating temperature differs from the ambient temperature. This paper investigates the impact of environmental temperature on resonance behaviors of a multi stack piezoelectric flextensional transducer (MSPFT). Various experiments were performed, where mechanical and electrical excitations were applied to the MSPFT in the controlled environmental temperatures ranges from 20 oC to 45 oC. The results show that raised temperatures have an adverse impact on the generated voltage and resonance frequency. In mechanical excitation, the generated voltage resonance peak and the resonance frequency are significantly decreased with the increase of temperature. The resonance frequency shifted from 195Hz to 173Hz with increase of temperature from 20 oC to 45 oC for 0.1g mechanical excitation. This indicates that the piezoelectric coefficient slightly increases, the elastic modulus slightly decreases, and the mechanical damping significantly increases with the increases of environmental temperature. These findings are useful for a variety of energy harvesting applications, as well as the future development of innovative piezoelectric transducers in high-temperature environments.