Harvesting electrical energy from thermal energy sources using pyroelectric conversion techniques
has been under investigation for over 50 years, but it has not received the attention that thermoelectric energy
harvesting techniques have during this time period. This lack of interest stems from early studies which
found that the energy conversion efficiencies achievable using pyroelectric materials were several times less
than those potentially achievable with thermoelectrics. More recent modeling and experimental studies have
shown that pyroelectric techniques can be cost competitive with thermoelectrics and, using new temperature
cycling techniques, has the potential to be several times as efficient as thermoelectrics under comparable
operating conditions. This paper will review the recent history in this field and describe the techniques that
are being developed to increase the opportunities for pyroelectric energy harvesting.
The development of a new thermal energy harvester concept, based on temperature cycled
pyroelectric thermal-to-electrical energy conversion, are also outlined. The approach uses a resonantly
driven, pyroelectric capacitive bimorph cantilever structure that can be used to rapidly cycle the temperature
in the energy harvester. The device has been modeled using a finite element multi-physics based method,
where the effect of the structure material properties and system parameters on the frequency and magnitude of
temperature cycling, and the efficiency of energy recycling using the proposed structure, have been modeled.
Results show that thermal contact conductance and heat source temperature differences play key roles in
dominating the cantilever resonant frequency and efficiency of the energy conversion technique. This paper
outlines the modeling, fabrication and testing of cantilever and pyroelectric structures and single element
devices that demonstrate the potential of this technology for the development of high efficiency thermal-toelectrical
energy conversion devices.