Coupling of piezo- and pyro-electric effects in miniature thermal energy harvesters

Abstract

Thermal energy harvesting from ambient heat into electricity is of interest due to its wide potential applicability. This paper demonstrates a moving beam thermal energy harvesting mechanism exploiting both pyro-and piezo-electric effects simultaneously, for use adjacent to a heat source with small temperature variations at low frequency (below 0.1 Hz). For the first time, the relative contributions of these two mechanisms in such a device is established both theoretically and experimentally, and a dynamic model is provided. The relative phase of the contributed currents is shown to be a critical factor, and methods are introduced to optimise this phase relationship, particularly by selection of the mechanical configuration. The reported prototype achieves around 0.4 µW for a temperature difference of around 15 K at frequency 0.02 Hz with an optimal condition in the fixed-fixed configuration about 90 % above the fixed-free end configuration.

A Flexible Bilayer Actuator Based on Liquid Crystal Network and PVDF–TrFE for Low‐Grade Waste Heat Harvesting

“…These results confirm that the fabricated generator can effectively convert the low‐grade heat to electricity. Thus, this generator can be used to in many situation, such as the cycle compressors in the cooling and refrigeration systems; [ 32 ] or sunlight irradiation. [ 5 ]…”

Current and Future Trend Opportunities of Thermoelectric Generator Applications in Waste Heat Recovery

“…Some manufacturers have tried to search for cost-effective TE material compositions acting to minimize the effects of low productivity. The forming of TEGs considers a process approach to optimize the whole system because the TEMs have low performance [12]. An elaborated presentation of TEG applications is essential for different challenges that confines the industrial fulfilment of TEGs.…”

Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

“…However, due to the limited lifespan of batteries, it severely restricts the continuous operation of smart sensor devices and replacing batteries regularly can cause high costs. To solve these problems, developing self-powered devices by using some approaches to harvest ambient energy, for instance, solar energy [ 1 , 2 , 3 ], wind [ 4 , 5 , 6 ], tidal energy [ 7 ], thermal energy [ 8 , 9 ], mechanical vibration [ 10 , 11 ], and pyroelectric energy [ 12 , 13 ], is a feasible program. The commonly used energy harvesting mechanism is piezoelectric [ 14 , 15 , 16 , 17 ].…”