A Metal-Oxide Gas Sensor Based on an Aerosol Jet Printing Technology Featuring a One Second Response Time

This paper reports on the design and fabrication of metal-oxide gas sensors, utilizing aerosol jet printing, combined with microhotplates fabricated through a process based on the industrial PolyMUMPs technology. Fabrication is complemented with in-house post-processing steps that do not require additional alignment or dry etching equipment, which greatly reduces the fabrication complexity. Aerosol jet printing is used to deposit thin homogeneous metal-oxide films, with micron thickness. A heating temperature over 300 °C is achieved by the microhotplates, at ~24 mW of power consumption. Measurement results demonstrate that the fabricated sensors exhibit good sensitivity and feature ultra-fast response times - as low as 1.2 seconds.