A microfabricated carbon dioxide sensor for portable applications

The reliable detection of carbon dioxide (CO₂) emissions is a key step towards the ability to mitigate CO₂ levels in the atmosphere. At present, many CO₂ sensors exist, but they all require on the order of watts of power, therefore, they are not suitable for long term unattended operation. In this paper, we present a new design for a microfabricated CO₂ sensor that operates at room temperature with very low power input. The device uses the selective adsorption of CO₂ in a room temperature ionic liquid (RTIL) followed by an electrochemical reaction at a gold electrode to detect the presence of CO₂. We find that the device is able to measure normal atmospheric levels of CO₂ with high reliability using less than 10 μW of power. This advance will enable a new class of portable CO₂ sensors to be constructed.