Self-powered AlGaN/GaN HEMT-based sensor integrated with rotational TENG for comprehensive water quality analysis

Abstract

High-electron-mobility transistors (HEMTs) are recognized for their high electron mobility, exceptional sensitivity and linear response, making them ideal for precise sensing applications. This study introduces a novel, self-powered monitoring system that integrates a rotating triboelectric nanogenerator (R-TENG) with an AlGaN/GaN HEMT sensor for detecting pH levels, heavy metals (Cr^6 +, As³⁺, Pb²⁺), pesticides (chlorpyrifos) and microplastics (polystyrene) under aquatic conditions. The encapsulated device constructed with acrylic layers and magnetic coupling, operates reliably underwater, achieving a 75 V output at 7 μA at 100 rpm. Demonstrating high pH sensitivity (-13.93 mA/pH) with strong linearity (R² = 0.98), HEMT sensor effectively detects pollutants at trace levels, distinguishing concentrations down to nanomolar ranges. Operating at a peak power of 76.64 μW and switching frequency of 60 Hz, this innovative system facilitates continuous, long-term environmental monitoring, harnessing water wave energy to enable sustainable pollutant detection in remote or harsh aquatic environments.