Piezoelectric conversion of thermal energy

Our innovative Piezoelectric Thermomagnetic Generator (PTMG) is designed to convert low-grade thermal energy into usable electrical power. By integrating a thermo-magnetic film generator with a piezoelectric energy conversion layer, this device transforms waste heat into mechanical motion, which is then converted into electricity—offering a promising solution for powering off-grid electronics, IoT systems, and wearable medical devices.

The generator operates effectively across a wide temperature range, with optimal performance observed around moderate heat source temperature near 100°C. Within this range, the device achieves stable resonant operation, characterized by distinct frequency patterns that enable efficient energy conversion. At lower temperatures, reduced heat flow results in slower, non-resonant cycles, while excessive heat may lead to operational instabilities due to heat accumulation in the thermo-magnetic material.

By integrating a voltage-doubling rectification circuit, the PTMG successfully converts harvested AC power into a usable DC output with reasonable power per footprint when compared to its induction based TMG device counterpart. This breakthrough in energy harvesting technology paves the way for self-powered electronic systems, reducing dependence on batteries while utilizing widely available waste heat.

Figure a) Layout of TMG with Piezoelectric layer.

Figure b) Output of TMG while operating in resonant self-actuation mode.

Further information on this topic can be retrieved from the IECAT 2024 talk in the  YouTube video: "IECAT 2024 Day 3, Session 4: Remarkable actuator application" (Link to YouTube video)

Contact

M.Sc. Maxim Wischnewski [Contact]