Extreme-low power NaOCl sensor using EG-CNTs as Sensing Element

This paper presents a chemical sensor employing electronic-grade carbon nanotubes (EG-CNTs) as the active sensing element for sodium hypochlorite (NaOCl) detection. EG-CNTs are aligned between the microelectrodes with a gap distance of 2 mum by using AC dielectrophoretic (DEP) technique on a glass substrate. A microfluidic chamber is created by bonding a PDMS microchannel of 1 mm width onto the glass substrate on which pairs of microelectrodes are fabricated. This microfluidic chamber encloses the EG-CNTs sensing elements and ensures that they are submerged in a chemical solution of certain volume during experimental tests. We demonstrated the electrical responses of the sensor to NaOCl solution with different concentrations at room temperature. To fully study the properties of the sensor when used to detect NaOCl, different configurations of flow rate and total volume injected into the channel are carried out as well.