Elasticity‐Amplified and Chemically Robust Magneto‐Triboelectric Hybrid Generator for Durable Droplet Energy Harvesting and Self‐Powered Dual‐Parameter Sensing

Raindrops and ambient water droplets constitute a ubiquitous and renewable mechanical energy source for self‐powered systems. However, droplet energy harvesters often exhibit very short output duration and poor stability of metal electrodes in wet and corrosive environments. Here, a droplet‐based triboelectric and magnetoelastic hybrid generator (DTMG) is introduced, which integrates a magnetoelastic film (MEF) with electrodes composed of laser‐induced graphene (LIG) and fluorine‐doped LIG (FLIG). LIG provides excellent mechanical stability and strong adhesion to the substrate, while FLIG offers enhanced hydrophobicity and chemical durability, preventing corrosion of the electrode. The MEF supported by a cantilever‐inspired elastic supporter (ELS), stores the impact energy of droplets as elastic potential energy and releases it as long‐duration magnetoelastic generator (MEG) output. As a result, the hybrid generator extends output duration by up to 3769% relative to previously reported droplet‐driven electromagnetic generators while retaining the high‐output characteristics of the droplet‐based electricity generator (DEG). Moreover, the device functions as a self‐powered sensor in which the MEG signal is processed to determine droplet height and the DEG signal is correlated with ion concentration based on height‐dependent charge generation. This synergistic platform offers a robust and sustainable solution for droplet‐driven energy harvesting and self‐powered sensing in aqueous environments.