Field‐Regulated Triboelectric Nanogenerators for Enhanced Energy Conversion

ABSTRACT Triboelectric nanogenerators (TENGs) provide a versatile platform for distributed mechanical energy harvesting and self‐powered sensing. However, their practical deployment remains constrained by insufficient surface charge density, high output impedance, impedance mismatch, and environmental instability, particularly under low‐frequency and low‐intensity mechanical excitation. To move beyond purely mechanically driven contact electrification, optical, thermal, magnetic, and electric fields have recently been introduced into TENG systems to regulate interfacial charge generation, separation, transport, and retention. Unlike reviews centered on the simple structural integration or output superposition of otherwise independent energy‐harvesting units, this review focuses on mechanistic external‐field coupling and adopts field‐assisted charge modulation as a unifying framework for analyzing multifield‐coupled TENGs. Starting from Maxwell's displacement current, the fundamental working mechanism of conventional TENGs and the key parameters governing their output performance are discussed. Coupling mechanisms involving localized surface plasmon resonance, photon‐generated carriers, pyroelectric effects and heat‐excitation effects, magnetic nanomaterials, magnetically assisted structures, charge injection, and charge pumping are then highlighted. Finally, current challenges and future opportunities in unified theoretical modeling, field‐responsive materials, system‐level integration, power management, and long‐term reliability are discussed. By linking external‐field coupling mechanisms with materials design and device architecture, this review provides guidance for developing high‐output, adaptive, and multifunctional self‐powered systems.