Elastic rebound engineering via leaf venation mimicry: boosting droplet spreading for high-performance triboelectric nanogenerators

Droplet-based energy generator (DEG) has emerged as a promising platform for sustainable micro-energy harvesting, yet improving its energy conversion efficiency remains a primary research focus. In this work, we report an artificial leaf droplet-based energy generator (ALDEG) that mimics the interspaced soft-rigid venation pattern of plant leaves to enhance energy conversion by promoting droplet spreading. Testing reveals that the optimal interplay between membrane energy absorption and elastic rebound, modulated by venation pattern, leads to a 216% enhancement in voltage output and 233% enhancement in current output compared to conventional planar DEGs. An analytical model is developed to describe the relationship between the artificial venation pattern and droplet spreading dynamics, elucidating a "soft-over-hard" principle in which membrane elastic rebound enhances droplet spreading and thus charge generation. Furthermore, a multitier ALDEG architecture inspired by rainfall cascading through forest canopies demonstrates scalable energy harvesting and exhibits robust performance when powering a diverse range of electronic devices. This work establishes a new bio-inspired design framework for DEGs, demonstrating how biomimicry can be harnessed to modulate the substrate structure of DEGs for enhanced performance. The ALDEG platform holds promise for powering self-powered systems for autonomous environmental monitoring, smart agriculture, and other decentralized applications.