Integration of RF Technology and Graphene Oxide for Wireless Humidity Sensing

S. Aryal, A.B. Kaul
University of North Texas,
United States

Keywords: Radio frequency, antenna, copper, graphene, graphene oxide, wireless, sensor, humidity sensor, HFSS


In the era of the internet, wireless sensors - particularly those utilizing Radio Frequency (RF) technology - epitomize a contemporary advancement in sensor design, and offer a paradigm shift in design by enabling remote access to critical information through wireless sensor networks. The current sensing technologies are based on resistive and capacitive approach in which the electrical properties of the material are often dominated by DC conductivity. However, the influence of it typically diminishes on RF spectrum and additional electrical properties such as impedance and dielectric constant become more pronounced, enabling tailored and nuanced understanding of the material's electrical properties. Being cost effective, power efficient and compatible with miniaturization, RF sensing approach not only elevates the capabilities of sensors but also aligns seamlessly with the broader Internet of Things (IoT) framework. This research employs RF sensing strategy to measure the humidity of the environment using Graphene Oxide (GO) as a sensing material. The copper (Cu) antenna is fabricated on the silicon dioxide/silicon substrate which serves as a wireless transmitter and is compared with the simulation result of the antenna using ANSYS HFSS simulation tool. The rf parameters of the antenna are measured with respect to humidity change to quantify the sensing behavior. Notably, the bio compatible solvents are used to prepare the ink of the GO which is characterized using Raman spectroscopy on the deposited film of GO. This research contributes to the advancement of wireless sensor technologies with potential applications in diverse IoT scenarios, showcasing the potential of state-of-art nanocarbon and 2D materials in enhancing sensing capabilities.