A Humidity Sensor Based on Bacterial Nanocellulose Membrane (BNC)

This article presents the development of a humidity sensor based on bacterial nanocellulose membrane (BNC) produced from Komagataeibacter xylinus. BNC has a porous surface that absorbs water and therefore it changes the mechanical and electrical properties of the membrane. As the amount of water inside the membrane increases the capacitance of the membrane also increases. The capacitance of the BNC was measured in different values of temperature (from 30° to 100°) and relative humidity (from 30% to 100%). Chronoamperometry was used as a reproducibility test and the result was a linear and more precise variation for RH over 50% and a temperature of 30°. The measurements showed a combined sensitivity of −4.13 nF/°C in relation to the temperature, and +492 nF/(%RH) and +66.8 nA/(%RH) in relation to the relative humidity.