Abstract
A wireless vapor sensor based on 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 kHz/%RH ± 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.
Original language | English (US) |
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Article number | 6690163 |
Pages (from-to) | 1459-1466 |
Number of pages | 8 |
Journal | IEEE Sensors Journal |
Volume | 14 |
Issue number | 5 |
DOIs | |
State | Published - May 2014 |
Keywords
- Graphene
- Quantum capacitance
- Sensor
- Varactor
- Wireless