Electrospun PVA/TiC Nanofibers for High Performance Capacitive Humidity Sensing

In this work, high performance capacitive type humidity sensors are fabricated based on polymeric PVA/TiC nanofibers by reinforcing TiC NPs into the polyvinyl alcohol matrix following the most cost-effective electrospinning technique. The fabricated nanofibers are then characterized by SEM, XRD and FTIR which reveal the strong bonding interaction of both the precursors. The humidity sensing capability of PVA/TiC nanofibers mat is determined at room temperature in the frequency range of 100 Hz - 100 kHz. The fabricated humidity sensor displays an excellent capacitive humidity response in terms of linear capacitive behavior, short response/recovery time of 2.8/1.7 s, high sensitivity of 1,277,355.0%, good repeatability and excellent stability, at the frequency of 100 Hz. Moreover, in the humidification and dehumidification cycle, the sensor exhibits a small hysteresis of 2.8% at 100 Hz. The fabricated nanofibers-based sensor also indicates high sensitivity to every 1% RH variation from 1% to 90% RH. These favorable characteristics of PVA/TiC nanofibers enable the fabricated humidity sensor to determine the human respiration and can differentiate between slow and fast breath from the nose and mouth or before and after the exercise, respectively.