Greenhouse Gas Molecule CO2 Detection Using a Capacitive Micromachined Ultrasound Transducer.

We manufd. and tested a capacitive micromachined ultrasound transducer (CMUT)-based sensor for CO2 detection at environmentally relevant concns. using polyethylenimine as a CO2 binding material. The assembly of a sensing chip was 10 × 20 mm, and up to 5 gases can potentially be detected simultaneously using a masking technique and different sensing materials. The limit of detection was calcd. to be 0.033 CO2 vol. % while the limit of quantification was calcd. to be 0.102%. The sensor exhibited a linear response between 0.06% and 0.30% CO2 while concns. close to those in flue gas can also be measured using diln. with inert gas. [on SciFinder(R)]