Gas sensing using embedded piezoresistive microcantilever sensors

A novel gas sensor design has been developed using embedded piezoresistive microcantilever (EPM) technology. In this design, a small piezoresistive microcantilever is embedded or partially embedded into a sensing material that swells slightly upon analyte exposure. This swelling is measured as a simple resistance change in the piezoresistive cantilever, and thus the analyte is detected. Here, we have used an Ni-containing polymer, poly(ethylene oxide), as the active sensing material. This EPM sensor is then used to detect the presence of carbon monoxide gas. For small exposures, the sensor is fully recoverable; however for very large exposures, irreversible chemical changes in the polymeric sensing material occur.