Network Tunability of Natural Rubber Compositions Unlocks Partially Sustainable Triboelectric Nanogenerator

ABSTRACT

Triboelectric nanogenerators (TENG) have emerged as a promising candidate for sustainable energy harvesting; however, most materials used in TENG fabrication rely on petroleum‐sourced polymers. Notably, a few studies have used sustainable materials, such as natural rubber (NR). In a filler‐free system, the NR‐TENG output is low. In most such cases, fillers were added to tune the NR‐TENG properties. However, these fillers are not sustainable. Hence, it is critical to devise a strategy to improve the NR‐TENG output under filler‐free conditions. Herein, we report a filler‐free strategy that leverages precise control over the sulfur network to enhance the NR‐TENG output. The optimized sample demonstrated exceptional durability over 90 000 cycles, a power density of 4.53 W/m ² , and a short‐circuit current of 23.2 µA, representing ∼700% and ∼300% enhancements over the best‐reported NR‐based systems. Mechanistically, performance is governed by the interplay between sulfur content and cross‐link‐driven deformation behavior. A theory‐driven mathematical model was derived to predict TENG output and demonstrated strong agreement with experimental findings. The optimized TENG was pressure‐sensitive, with a sensitivity of 0.035 V/kPa. As a prototype, the technology was applied to develop a self‐powered boundary system that enables accurate, real‐time sports monitoring with minimal reliance on human intervention.