Drop-coated metal-oxide gas sensor on polyimide foil with reduced power consumption for wireless applications
Highly miniaturized low-power drop-coated metal-oxide gas sensors on polyimide foil are presented. Drop-coating of SnO2-based material was successfully achieved on transducers as small as 15 μm on polyimide, a substrate compatible with the printed electronics industry. The sensors showed a very good chemoresistive response when exposed to CO and NO2. The power consumptions of the sensors ranged from a minimum of 7.7 mW for the smallest hotplate at 200 °C to a maximum of 28.4 mW for the largest device at 250 °C in continuous mode of operation. In a pulsed mode, their consumption was reduced to the sub-milliwatt range for the 15 μm wide heaters while keeping a good chemoresistive response, widening their use to low-power applications, such as for wireless systems. The sensors were interfaced to a custom-made electronic circuitry with a readout based on time-to-digital conversion to minimize the amount of electronic components and reduce the power consumption. The power consumption of the 15 μm wide sensor was 680 μW in pulsed mode, while the sensor system exhibited a total power consumption of 1.9 mW. © 2011 Elsevier B.V. All rights reserved.
Record created on 2012-01-23, modified on 2016-08-09