Carboxymethyl Cellulose Grafted Acrylic Acid Hydrogel Membrane as Humidity Sensor

Humidity sensors are widely used to characterize electrical components as the working will be greatly affected by the presence of humidity. A study is conducted here with carboxymethyl cellulose grafted with acrylic acid based hydrogel membranes and its function as an absorbing layer in a resistive-based humidity sensor. The hydrogel membrane is prepared by coating the electrodes with 2 wt % CMC solution (in 3: 1 water: ethanol mixture). CMC g- AA membrane is cross-linked with citric acid. The measurement results show that the CMC g- AA hydrogel can function as humidity sensor at high humidity range. The sensor was tested by measuring the resistance of the CMC hydrogel membrane at various relative humidity. Sensitivity and reliability of humidity sensors depend on the design of electrical components and the characteristics of material used as absorbing layer