Zinc Oxide Nanowires Deposited on Polymeric Hotplates for Low-power Gas Sensors

Zinc oxides (ZnO) nanowires were successfully deposited on plastic low-power micro-hotplates using the thermal oxidation technique. Metallic zinc layer was deposited on the sensing transducer by RF magnetron sputtering and then oxidized in a controlled atmosphere in order to obtain ZnO nanostructures. Morphological investigations confirmed the nanometric dimensions of the fabricated nanostructures. The n-type behavior of the nanostructured material was evaluated towards different chemical species to highlight the electrical properties of the materials. Calibration curves for the detection of several chemical species were defined. © 2012 The Authors. Published by Elsevier Ltd

Multi sensor platform on plastic foil for environmental monitoring

AbstractWe report on multi-sensor platforms on plastic foils for environmental monitoring. Polymer-based capacitive sensors for humidity and volatile organic compounds (VOC)s, semiconducting metal oxides (MOX) based chemoresistive sensors for reducing/oxidizing gases and a Pt thermometer have been integrated together on a polyimide sheet and their performances characterized. The MOX gas sensors exhibited good sensitivity to CO and ethanol. The differential operation of the capacitive humidity sensors resulted in increased signals and reduced response/recovery times

Ultra-low power metal oxide gas sensor on plastic foil

We report on the design and fabrication of ultra-low power metal-oxide (MOX) gas sensors on plastic foils envisioning their fabrication at large scale and low cost. A complete sensor solution is presented including its packaging at the foil level and the driving/readout circuitry. The latter allowed the sensor to operate in pulsed temperature mode to reduce the power consumption in the sub-mW range. Gas measurements under CO, CH4 and NO2 have proven the proper operation of the sensor. These devices are being developed targeting wireless applications

ULTRA-LOW POWER METAL-OXIDE GAS SENSOR ON PLASTIC FOIL

ABSTRACT We report on the design and fabrication of ultra-low power metal-oxide (MOX) gas sensors on plastic foils envisioning their fabrication at large scale and low cost. A complete sensor solution is presented including its packaging at the foil level and the driving/readout circuitry. The latter allowed the sensor to operate in pulsed temperature mode to reduce the power consumption in the sub-mW range. Gas measurements under CO, CH 4 and NO 2 have proven the proper operation of the sensor. These devices are being developed targeting wireless applications

Micro-solid oxide fuel cells as power supply for small portable electronic equipment

Micro-solid oxide fuel cell (SOFC) systems are anticipated for powering small, portable electronic devices, such as laptop, personal digital assistant (PDA), medical and industrial accessories. It is predicted that micro-SOFC systems have a 2-4 higher energy density than Li-ion batteries [1]. However, literature mainly focuses on the fabrication and characterization of thin films and membranes for micro-SOFC systems [2-12]; the entire system approach is not yet studied in detail. We will therefore discuss in this paper the entire approach from the fabrication of thin films and membranes up to the complete system, including fuel processing, thermal management and integration

Integration of MOX gas sensors on polyimide hotplates

In this communication, we report on the integration of metal-oxide gas sensors on polymeric micro-hotplates made on polyimide and silicon substrates. Low-power consumption micro-hotplates with platinum electrodes and heaters were fabricated on polyimide membranes. Their thermal behavior was optimized using temperature probing at the micro-scale level coupled with thermal simulations. Tin oxide thick films were successfully integrated on these polyimide micro-hotplates using the drop coating technique. The annealing process of the tin oxide drops on the polyimide substrate was investigated and gas measurements are presented. Compared to the polyimide hotplates on silicon substrates, the hotplates made on polyimide sheets are simpler to process and more robust, and therefore, they are more suitable for the integration of metal-oxide films. Finally, a wafer level packaging technique using multiple polyimide layers was developed and led to a polymeric platform for metal oxide sensors. The technology is also promising for the integration of polyimide humidity sensors, of resistive and capacitive gas-sensitive polymeric films to realise fully flexible gas sensor arrays