Silver nanowires coated on cotton for flexible pressure sensors

Abstract

In this work, a simple dip-coating method is developed to form silver nanowire conductive networks on cotton fibers due to the hydrogen bonding between them, and conductive cotton sheets with high conductivity (10⁻⁴–10⁻⁵ Ω cm) and durability (agitated for more than 1500 min) are obtained to construct flexible pressure sensors. The fabrication process is of low cost and can be easily scaled up, and the bio-based flexible pressure sensors show very high sensitivity (3.4 kPa⁻¹), rapid response and relaxation time (<50 ms) and excellent stability (>5000 loading/unloading cycles). The working mechanism is theoretically studied and the results demonstrate that the layers of conductive cotton sheets play a key role in determining the performance of the flexible pressure sensors because it is closely related to the contact points. The flexible pressure sensors can effectively detect dynamic sound-driven vibrations (0.006 dB⁻¹), gentle external forces and muscle motions, illustrating their extensive applications in various fields such as voice recognition and robotic systems.