Liquid metal has exhibited great potential in escalating power density in both triboelectric nanogenerator and thermoacoustic systems. By coupling these two systems, Chinese scientists have proposed a highly reliable thermal power generator that could convert thermal energy into electric energy.
The exciting thing is the generator does not consist of any substantial moving parts. Besides, it is highly reliable and readily achieves a long life span. It also offers a theoretically high heat-to-electric conversion efficiency.
Scientists dubbed this new power generator as a thermo-acoustically driven liquid-metal-based triboelectric nanogenerator (TA-LM-TENG). It consists of two parts: thermoacoustic engine (TAHE) and liquid-metal-based triboelectric nanogenerator (LM-TENG).
The TAHE first converts thermal power into acoustic energy using thermal expansion and compression of the working gas. The LM-TENG then converts the acoustic energy into electrical energy through the coupling impact of contact electrification and electrostatic induction.
As shown in schematics, when heating the hot heat exchanger of the TAHE, the working gas in the engine will start spontaneous oscillation. The active gas’s oscillatory motion pushes the liquid metal column resonantly flowing upward and downward in the U-shaped tube.
Liquid metal is immersed and separated with the Kapton material periodically. The generator, therefore, generates an alternate electric potential difference at the electrodes. Electrical power is extracted from the TA-LM-TENG.
- Shunmin Zhu et al. Thermoacoustically driven liquid-metal-based triboelectric nanogenerator: A thermal power generator without solid moving parts, Applied Physics Letters (2021). DOI: 10.1063/5.0041415