High temperature printed micro-hotplate on polyimide foil for gas sensing and sampling
Résumé
Hybrid integration of different components (sampling/filtering, separation and detection) prevails in miniaturized analytical instruments for more selectivity and sensitivity. In this purpose, we report on flexible micro-hotplates usable for gas preconcentration and gas sensing. Our micro-hotplate is made on foil by using inkjet printing. Our technology provides flexibility in the design and paves the way for a new generation of cost-effective analytical instruments. Compared to previous work on Polyethylene Naphthalate (PEN) with silver as electrical conductor, it allows operating at high temperatures (up to 400˚C) thanks to the combination of gold nanoparticles-based heater and polyimide foil substrate. The foil gas preconcentrator is obtained by depositing an adsorbent onto of the foil hotplate whereas the fully printed metal oxide (MOX) sensor is implemented by inkjet-printing gold interdigitated electrodes covered by a metal oxide sensing layer. The Gas preconcentrator and the MOX sensor were successfully tested under benzene and carbon monoxide, respectively.