Triboelectric nanogenerators (TENGs) show promise for sustainable energy and self-powered sensing, but their reliability, output stability, and durability under cold and humid conditions remain challenging. Inspired by the “sliding-rearrangement” energy dissipation of vascular smooth muscle and the microstructure of rose petal papillae, this work presents a dual-bioinspired triboelectric material with bulk-surface co-modifications. 2,2,6,6-tetramethylpiperidin-N-oxyl-oxidized cellulose nanofibers@liquid metal core-shell droplets (∼350 nm) were fabricated by ultrasonic cavitation, mimicking smooth muscle morphology, and anchored into a waterborne polyurethane matrix, forming a reversible energy dissipation network. This yields a tensile strength of 15.4 MPa, elongation at break of 1590%, and toughness of 140.2 MJ·m−3. A rose-like microstructured array on the membrane surface achieves a water contact angle of 144.6°, indicating excellent hydrophobicity. These modifications enable a TENG output of 250 V, 8.19 µA, and 95 nC with only 0.93% voltage degradation after 12, 000 cycles. Performance is enhanced by improved dielectric polarization and charge storage in the bulk, and enlarged contact area and charge anchoring on the surface. The open-circuit voltage retention reaches 66% at −20 °C and 79% at 98% relative humidity. The device enables real-time monitoring of joint deformations, demonstrating an eco-friendly, robust self-powered sensing system for cold and humid environments.