High-Performance Microdroplet Tribogenerator Stimulated by Coupled Photonic and Phononic Excitations

The present research demonstrates the development of a μ-fluidic energy harvester (μEH) integrating mechanical, acoustic, and optical energy conversion mechanisms. The μEH transforms oil–water flow into a multiphase triboelectric energy harvester (TENG) by using oil as the continuous phase and water as the dispersed phase, minimizing electrolysis. The μEH uniquely functions as a microdroplet-operated transistor (μ-DOT), utilizing fluidic droplets as floating gates to modulate charge transport. A parametric optimization of two-phase flow characteristics (e.g., dispersed phase: 0.003–0.04 mL min–1; continuous phase: 0.01–0.08 mL min–1) attuned to the continuous phase viscosity reveals their direct influence on triboelectric output, yielding a power density of 10 kW m–3 under simultaneous mechanical (water 0.01 mL min–1, silicone oil 0.02 mL min–1), acoustic (700 Hz, 10 dB), and photonic (100 mW cm–2) excitations. A custom circuit rectifies the combined output to drive a 1.8 V light-emitting diode (LED), validating the scalability of the proof-of-concept prototype. The device architecture proposes a multielectrode topology and ultralarge-scale integration (ULSI)-compatible array design to enhance power harvesting efficiency, though experimental validation of the same remains pending further investigation. This fusion of droplet-operated floating gate field-effect transistor with hybrid energy harvesting mechanisms establishes a pathway for broader and more effective utilization of this technology on an industrial scale.