First experimental demonstration of a Self-Oscillating Fluidic Heat Engine (SOFHE) with piezoelectric power generation

In this paper, we present the working principle and first experimental demonstration of an innovative approach to harvest low-quality heat sources, the Self-Oscillating Fluidic Heat Engine (SOFHE). Thermal energy is first converted into pressure pulsations by a selfexcited thermo-fluidic oscillator driven by periodic phase change of a fluid in an enclosed channel. A piezoelectric membrane then converts this mechanical energy into an electrical power. After describing the working principle, an experimental demonstration is presented. The P-V diagram of this new thermodynamic cycle is measured, showing a mechanical power of 3.3mW. Combined with a piezoelectric spiral membrane, the converted electrical power generation achieved is close to 1μ W in a 1MΩ load. This work sets the basis for future development of this new type of heat engine for waste heat recovery and to power wireless sensors.