Time-domain modeling and experimental validation of an integrated thermoacoustic-liquid metal triboelectric nanogenerator

This study presents a time-domain model and experimental validation of an integrated thermoacoustic heat engine and liquid-metal-based triboelectric nanogenerator (TAHE-LM-TENG) system. Using a lumped acoustic-electric analogy, the model captures the coupled dynamic behavior of the thermoacoustic and triboelectric subsystems, enabling simulation of the complete energy conversion process under transient conditions. The system achieves self-sustained oscillations at a resonance frequency of 15 Hz, with a maximum acoustic power output of 31.3 W under a 300 W heat input. The triboelectric nanogenerator, employing a mercury–Kapton interface in sliding mode, generates an open-circuit voltage of 18.8 V and a short-circuit current of 3.2 μA in a single-layer configuration. Model predictions of onset temperature, acoustic pressure, and voltage output show good agreement with experimental measurements, with the onset temperature ratio captured within 82.9 % of the measured value. Further performance enhancement is demonstrated through parallel stacking of 32 TENG layers, achieving power and current densities of 0.1 W/m2 and 10.5 mA/m2, respectively. The novelty of this work lies in the development of a system-level time-domain model that dynamically couples the thermoacoustic and triboelectric subsystems of a hybrid gas–liquid energy harvester. The model provides a validated framework for analyzing and optimizing integrated TAHE-LM-TENG energy harvesting systems that operate without solid moving parts.