Nanofiber forests as a humidity-sensitive material

Nanofiber forests with high hydrophilicity and humidity-sensitivity are reported in this work. They are fabricated from polyimide (PI) by a plasma-stripping technique, and are utilized as a humidity-sensitive material in humidity sensors. In a relative humidity range of 50%–80%, nanofiber forest-based devices have capacitance ∼50% larger than that of PI-based sensors. Meanwhile, as the nanofibers construct a non-closed layer, the internal nanostructures are fully exposed to external environment, thus the absorption and desorption of moisture consume only a short time. Since the fabrication processes for both nanofiber forests and the devices are simple and fast, thus such a method may provide possibility for development of novel humidity sensors with high sensitivity and short response time.