2013/06/28 by David A. Deen, Deen, David A., Eric J. Olson +5
Chemical Engineering · Engineering · Physics and Astronomy · #Analytical Chemistry and Sensors #Capacitance #Capacitance probe #Capacitive sensing #Capacitor #Electrical engineering #Electrochemical sensors and biosensors #Electrode #Engineering #FOS: Physical sciences #Graphene #Materials science #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #Nanotechnology #Optoelectronics #Oxide #Physics #Quantum capacitance #Quantum mechanics #Variable capacitor #Varicap #Voltage #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.1306.6940
published in arXiv (Cornell University) (Cornell University) · 8 pages, 7 figures
arxiv created 2013/06/28 · openalex publication_date 2013/06/28 · arxiv updated 2013/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A wireless vapor sensor based upon the quantum capacitance effect in graphene is demonstrated. The sensor consists of a metal-oxide-graphene variable capacitor (varactor) coupled to an inductor, creating a resonant oscillator circuit. The resonant frequency is found to shift in proportion to water vapor concentration for relative humidity (RH) values ranging from 1% to 97% with a linear frequency shift of 5.7 +- 0.3 kHz / RH%. The capacitance values extracted from the wireless measurements agree with those determined from capacitance-voltage measurements, providing strong evidence that the sensing arises from the variable quantum capacitance in graphene. These results represent a new sensor transduction mechanism and pave the way for graphene quantum capacitance sensors to be studied for a wide range of chemical and biological sensing applications.