Surface-engineered ultralow graphene nanoplatelet/PDMS composites for high-performance triboelectric energy harvesting

Triboelectric Nanogenerators (TENGs) have emerged as promising candidates for converting low-frequency mechanical energy into electricity to power distributed Internet of Things (IoT) devices and smart electronics. However, achieving high-performance TENG using environmentally friendly, scalable, and cost-effective fabrication strategies remains a critical challenge. In this work, a high-performance contact-separation-mode TENG is developed using polydimethylsiloxane (PDMS) and printing paper (PP), synergistically enhanced by ultralow loading of graphene nanoplatelets (GNP) and stainless-steel mesh-based surface engineering. A PDMS/PP TENG was first optimized by controlling the thickness of the PDMS layer. Subsequently, embedding an ultralow concentration of GNPs (0.15 wt.%) into the PDMS matrix significantly improved the dielectric properties, resulting in a 280% increase in output power density relative to the control device. To further improve performance, micro-structured surface engineering was introduced via mechanical imprinting with stainless-steel meshes of different grit sizes. Among the investigated configurations, the 700-mesh-patterned 0.15 wt.% GNPs@PDMS triboelectric layer provided optimal interfacial contact and effective surface area, resulting in substantial output enhancement. This optimized TENG delivered a power density of ∼1.88 W/m 2 , which is 147% higher than the non-patterned 0.15 wt% GNPs@PDMS TENG and an 840% improvement over the pristine PDMS-based TENG. As proof of concept, a fabricated TENG with optimized mesh-patterned 0.15 wt% GNPs@PDMS demonstrated excellent utility by rapidly charging capacitors and successfully powering 290 green light-emitting diodes (LEDs) and a commercial hydro-thermometer. This work presents a simple, scalable, and environmentally friendly strategy to advance high-performance TENGs, highlighting their strong potential for sustainable, self-powered, and green-energy applications.