This paper presents a wireless, passive, remote query CO2 sensor comprising a ribbon-like magnetoelastic thickfilm coated with a mass-changing CO2 responsive polymer synthesized from acrylamide and isooctylacrylate. In response to a magnetic field impulse, the magnetostrictive magnetoelastic sensor vibrates at a characteristic resonant frequency that is inversely dependent upon the mass of the attached CO2 responsive polymer. The mechanical vibrations of the magnetostrictive sensor launch magnetic flux, which can be detected remotely using a pickup coil. By monitoring the resonant frequency of the passive sensor, the atmospheric CO2 concentration can be determined without the need for physical connections to the sensor or specific alignment requirements. The effect of humidity and the CO2 responsive copolymer composition on the measurement sensitivity are reported. Greatest sensitivity is achieved with a polymer comprising a 1:1 mole ratio of acrylamide to isooctyl acrylate. A 0.7% change in atmospheric CO2 concentration can be detected for a 20 μm thick polymer coated sensor.
|Number of pages||5|
|Journal||Journal of Environmental Monitoring|
|State||Published - 2000|
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health
- Management, Monitoring, Policy and Law