Enhancing Triboelectric Output via Plasma-Engineered Surface Roughness on PDMS Films

For triboelectric nanogenerator (TENG) operating under tight footprint limits, raising output per unit area is essential. Here, we use oxygen-plasma treatment as a single, scalable knob to control the surface roughness of polydimethylsiloxane (PDMS) and examine how this affects device output. Plasma exposure generates micro/nanoscale wrinkles (and, at long times, hierarchical textures) without changing bulk composition. Surface topography is quantified by AFM using root-mean-square roughness (R q ) and the developed surface area ratio (S dr ), and the morphology is cross-checked by SEM. We find that roughness increases monotonically with plasma time and the TENG output rises in parallel. Under our test conditions, open-circuit voltage ( V oc ) shows a stronger quantitative association with R q, whereas short-circuit current (I sc ) correlates more closely with S dr . Because R q and S dr covary during oxygen-plasma treatment, these results are interpreted as quantitative associations rather than causal proof. Overall, the study provides a simple, lithography-free route and clear roughness-to-performance guidelines for achieving high output density in PDMS-based TENG.