Noise Characterization of Graphene Sensors

This study investigates the operational dynamics and challenges of graphene-based sensors, focusing on refining data measurement and processing techniques to ensure accurate identification of chemical compounds in different gas atmospheres. The research highlights the importance of sensor cleanliness and the use of analytes with physical properties matching the measurement environment. The cleaning process involves using isopropyl alcohol and heating the sensor to 70°C, with cooling facilitated by the sensor's low thermal mass. This study also explores injecting saturated liquid onto the sensor to eliminate issues related to pressure and gas composition variations. Experimental methods include measuring the graphene sensor in the spectral domain using a setup that minimizes resistive noise and optimizes sensor response. Key variables such as voltage, resistor noise characteristics, signal path to the amplifier, system temperature, and bonding materials are fine-tuned to achieve the lowest parasitic noise. Time-domain and frequency-domain measurement techniques are employed to correlate resistance and impedance changes with gas concentrations, respectively.