▎ 摘　　要

High-sensitivity ammonia gas sensors are paramount to many fields in our industries and lives. Due to its complicated fabrication processes, large size and long recovery time of most existing ammonia gas sensors, we present a micron-scale graphene-based ammonia gas sensor using aerosol-jet printing technology. The graphene sensor exhibited high response sensitivity (similar to 4.64 % for 4.35 ppm NH3 and similar to 52.01 % for 97.19 ppm NH3, respectively), short adsorption / desorption time ranging from 50 s to 150 s, good reversibility and repeatability. Further employment of micro-heater close to the sensing line reduced desorption time more than similar to 14.3 % when 10 V being applied onto the heater. Such design of the ammonia gas sensor by aerosol-jet printing can give an insight for graphene-based ammonia gas sensors, which may pave a way for the convenient integration with other sensors in portable instruments for coal miners and pathfinders etc. (C) 2020 Elsevier B.V. All rights reserved.