Bending-Stable Pressure Sensor Based on Natural Wood Nanofibers for Ultra-Low Detection Limit.

Flexible pressure sensors, essential for intelligent electronic skins, are valued for their versatility and integration. However, the inherent coupling between the pressure and bending strain effects limits their sensing features atop curved surfaces and hinders ultralow detection thresholds. Inspired by natural nests, we present a bioinspired all-fiber flexible pressure sensor that effectively decouples pressure and bending strain. Mimicking the interwoven fiber networks, the proposed device employs a fully fiber-based structure derived from natural wood to replicate the pressure-bending strain decoupling mechanism. This configuration isolates pressure from strain under bending deformation through synergistic modulation of the dielectric constants and interelectrode spacing. Therefore, it first enables precise pressure detection even on curved and dynamic surfaces. Besides the exceptional conformability and long-term stability, its detection limit achieves a record of 0.03 Pa. Furthermore, this natural wood-based sensor demonstrates recyclability through a dissolving-reproducing strategy and spatial pressure mapping through machine learning, offering a sustainable and cost-effective solution for physiological and environmental monitoring.