Title :
A passive wireless graphene oxide based humidity sensor and associated portable telemetry unit
Author :
Zhang, Chenghui ; Huang, J.Q. ; Huang, Q.A.
Author_Institution :
Key Lab. of MEMS of Minist. of Educ., Southeast Univ., Nanjing, China
Abstract :
This paper presents a passive wireless humidity sensor based on graphene oxide and its associated portable telemetry unit. The sensor consists of a CMOS interdigital capacitive humidity-sensitive sensor die and a fixed planar spiral inductor on an organic substrate (FR-4), forming an inductor-capacitor (LC) tank circuit. The resonant frequency of the tank is dependent on the sensor capacitance, which changes in response to the humidity. The sensitivity of the sensor is improved significantly by using graphene oxide as sensing material. The sensor is interrogated wirelessly by using our homemade portable telemetry unit. The reader is based on a standing wave ratio (SWR) bridge to measure the real part of the readout coil impedance, thus addressing the need for a low-cost, portable reader for the LC-type passive wireless sensors. Measurements show a sensitivity of -18.75 kHz/%RH over a range of 15-90% RH.
Keywords :
CMOS integrated circuits; LC circuits; capacitance; capacitive sensors; graphene; humidity sensors; inductors; portable instruments; telemetry; CMOS interdigital capacitive humidity-sensitive sensor die; CO; fixed planar spiral inductor; inductor-capacitor tank circuit; organic substrate; passive wireless graphene oxide; portable telemetry unit; readout coil impedance; resonant frequency; sensitivity; standing wave ratio bridge; Graphene; Humidity; Inductors; Resonant frequency; Telemetry; Wireless communication; Wireless sensor networks; Humidity sensor; LC sensor; passive sensor; wireless sensor;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013 Transducers & Eurosensors XXVII: The 17th International Conference on
Conference_Location :
Barcelona
DOI :
10.1109/Transducers.2013.6626756
