In this article, the development of an electrochemical methane sensor is presented. The mixed potential based sensor is based on tin doped indium oxide (ITO) and platinum electrodes and yttria-stabilized zirconia (YSZ) electrolyte. The sensor was fabricated using the inexpensive tape-cast method. The sensor responded to methane with a response time of 15 s. The staircase response to methane indicated a 44 mV sensor response to 100 ppm of methane. The sensor response indicated a log-linear relationship with the methane concentration. Upon 500 hrs of sensor testing, a 5% reduction in methane sensitivity was observed. The cross-sensitivity study on the sensor indicated minimal interference to NO, NO 2 , and CO 2. To improve the sensitivity to methane, a signal conditioning method referred to as the pulsed discharge technique (PDT) was applied. A fourfold increase in methane sensitivity was observed when the sensor was subjected to PDT. Future studies include the miniaturization of the sensor with integrated heater design.

In this article, a room temperature ammonia sensor on a paper substrate is reported. The electrochemical sensor is constructed using platinum electrodes and ionic liquid electrolyte. The amperometric staircase response shows discernible signal differentiation between each concentration of NH 3 (5-25 ppm). The rise time and fall time for the NH 3 sensor were found to be 8 s and 7 s respectively. The authors believe such a fast responding NH 3 sensor on a paper substrate has never been reported. The detection limit was deduced to be 1 ppm based on the sensitivity versus concentration plot. A 17% decrease in sensor response was observed over 30 days of testing. Implementing an antenna on the paper substrate co-located with the sensor for wireless operation is envisioned in future. © The Author(s) 2017. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0941704jes] All rights reserved.Manuscript submitted November 21, 2016; revised manuscript received February 1, 2017. Published February 9, 2017 Printing technologies are aiding and revolutionizing the burgeoning field of flexible sensors by providing cost-effective routes for processing diverse electronic materials at temperatures that are compatible with low-cost substrates.1,2 Simplified processing steps, reduced materials wastage, low fabrication costs and simple patterning techniques make printing technologies very attractive for cost-effective manufacturing of devices. One of the technologies currently used to print sensors is ink-jet printing. Inkjet printing technology offers lot of advantages toward sensor applications.3 Inkjet printing technology is environmentally friendly technology and cost-effective method. It is because inkjet printing technology does not use any hazardous chemicals to wash away unwanted metals on the substrate surface. It drops nano-sized ink on the desired position so that there are no by-products because it is an additive fabrication method. The advantages of the inkjet printing technology such as fast fabrication and ease of mass production helps to lower the cost of the inkjet-printed devices. Selecting the optimal substrates is one of the major issues in order to effectively realize low-cost and flexible inkjet-printed devices.Paper-based sensors are alternative technology for fabricating simple, low-cost, portable and disposable analytical devices for many application areas including clinical diagnosis, food quality control, and environmental monitoring. [4][5][6][7][8] The unique properties of paper which allow passive liquid transport and compatibility with chemicals are the main advantages of using paper as a sensing platform. Depending on the main goal to be achieved in paper-based sensors, the fabrication methods and the analysis techniques can be tuned to fulfill the needs of t...

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In this paper, the development of an electrochemical methane sensor is presented. The mixed potential based sensor is based on tin doped indium oxide (ITO) and platinum electrodes and yttria-stabilized zirconia (YSZ) electrolyte. The sensor was fabricated using the inexpensive tape-cast method. The sensor responded to methane with a response time of 15 s. The staircase response to methane indicated a 44 mV sensor response to 100 ppm of methane. The sensor response indicated a log-linear relationship with the methane concentration. Upon 500 hrs of sensor testing, a 5% reduction in methane sensitivity was observed. The cross-sensitivity study on the sensor indicated minimal interference to NO, NO2, and CO2. To improve the sensitivity to methane, a signal conditioning method referred to as the pulsed discharge technique (PDT) was applied. A fourfold increase in methane sensitivity was observed when the sensor was subjected to PDT. Future studies include the miniaturization of the sensor with integrated heater design.