Fabrication of multi-substrate electronics for ion enhanced humidity tracing in human-related smart sensing

Abstract

The advancement of smart sensing applications related to human activities underscores the need for humidity tracing to be highly sensitive, swift response, and capable of being fabricated flexibly across various substrates. This trade-off between gas adsorption and carrier transport represents a principal challenge for developing high-performance gas sensors. Here, a methodology is proposed to address this challenge by synthesizing lysine modified graphene oxide (GO-Lys) composite, which promotes both the absorption of water molecules and charge transport. The GO-Lys demonstrates a versatile and flexible capability for the fabrication of humidity sensors on various substrates, enabling the development of high-performance, printable, and wearable humidity sensors. The sensors proposed in this work demonstrate high sensitivity, swift response and recovery time, robust stability, high linearity, and low hysteresis. A maximum resistance response of (2.04 ± 0.39) × 10⁵ as humidity changes from 30 % to 90 % was observed by the sensor of GO-Lys@ITO. Additionally, equilibrium response and recovery times of 0.17 ± 0.02 and 0.25 ± 0.03 s, respectively, for humidity shifts from 40 % to 70 % was exhibited by GO-Lys@PET. Smart applications such as breath analysis, proximity detection, gesture recognition, and semantic recognition are researched by proposed high-performance sensors, highlighting potential to advance smart sensing technologies for human activities via humidity spectrum exploitation.