High-performance flexible self-powered pressure sensor based on Co-MOF/Ecoflex and PVDF/Ecoflex double triboelectric layer

Triboelectric nanogenerators (TENGs) are widely employed in self-powered pressure sensing, yet devices based on a single triboelectric layer have approached their performance ceiling. Herein, a “double triboelectric layer” strategy is proposed to construct a flexible, self-powered, single-electrode pressure sensor. The charge-generation layer employs Co-MOF with high surface area and excellent conductivity, blended into Ecoflex to maximize triboelectric charge output, while the charge-trapping layer incorporates highly electronegative PVDF into Ecoflex to suppress interfacial charge neutralization and expedite charge transport. Benefiting from the biomimetic micro-textured surface created by sandpaper templating, the enhanced charge-storage density afforded by Co-MOF-doped generation layer, and the elevated charge-transfer efficiency introduced by the PVDF-doped trapping layer, the device based on a double triboelectric layer boosts peak voltage to 86 V, which is a 177 % increase compared with the single-layer device (31 V). It delivers an ultrahigh sensitivity of 11.17 V kPa⁻¹ over 0–6 kPa and maintains stable operation beyond 11,00 cycles. With fast response and long-term reliability, the sensor accurately captures human motions and wrist-pulse signals. This architecture pioneers a pathway toward high-performance, self-powered sensors tailored for next-generation wearable electronics.