Microwatt-Powered, Low-Cost, Printed Graphene Oxide Humidity Sensors for Distributed Network Applications

[摘要] We report the design, fabrication, and characterization of novel conductometric humidity sensors that employ an ultrathin film of graphene oxide (GO) nanoflakes as transducing element. The GO film is deposited with a shadow mask using an electrospray emitter operated at atmospheric pressure; no post treatments-including annealing or doping- were applied to the GO sensors. The Van der Pauw electrode structure used in the sensor had 50 μm linewidths separated by 600 μm and was fabricated with the lift-off metallization technique. In dynamic humidity tests conducted at atmospheric pressure, the sensor tracks the response of a commercial sensor and reacts to changes in humidity in less than 500 ms. There is a quadratic dependence of the relative humidity on the sensor resistance for the relative humidity range between 3% and 63%, with more than a three-fold change in resistance over the range. The power consumption of the sensor is less than 30 μW while drawing 7 μA, and less than 15 μW while drawing 5 μA. Our devices are promising candidates for deployment in a distributed sensor network due to their low cost, small size, and low power consumption.

[发布机构] Edwards Vacuum LLC, Sanborn; NY; 14132, United States^1;Microsystems Technology Laboratories, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge; MA; 01239, United States^2

[效力级别] 能源学

[关键词] Distributed networks;Distributed sensor networks;Electrode structure;Electrospray emitter;Low-power consumption;Metallization techniques;Quadratic dependence;Relative humidity range