A wireless, remote query ammonia sensor.
This paper presents a wireless, remote query ammonia sensor comprised of a free-standing magnetoelastic thick-film coated with a polymer, poly(acrylic acid-co-isooctylacrylate), that changes mass in response to atmospheric ammonia concentration. The mass of the polymer layer modulates the resonant frequency the ferromagnetic magnetoelastic substrate, hence by monitoring the frequency response of the sensor, atmospheric NH3 concentration can be determined remotely, without the need for physical connections to the sensor or specific alignment requirements. The effect of copolymer composition, polymer film thickness, and relative humidity level (RH) on the sensitivity of the sensor were investigated. The sensor linearly tracks ammonia concentration below 0.8 vol.%, and tracks higher concentrations logarithmically; within the linear calibration range, a 0.02 vol.% change in NH3 concentration can be detected.
Materials Research Institute and Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
Q Y
QY
Cai
M K
MK
Jain
C A
CA
Grimes
D000179:Acrylates; D000641:Ammonia / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis; D001331:Automation; D004548:Elasticity; D004784:Environmental Monitoring / Q000295:instrumentation*; D005069:Evaluation Studies as Topic; D006813:Humidity; D008280:Magnetics; D011108:Polymers
D000179:Acrylates; D011108:Polymers; D000641:Ammonia; C071723:isooctyl acrylate; C036658:acrylic acid