Highly transparent humidity sensor with thin cellulose acetate butyrate and hydrophobic AF1600X vapor permeating layers fabricated by screen printing

A highly transparent humidity sensor has been developed on ITO patterned glass substrate. The fabrication included coating the fluoropolymer insulating layer and cellulose acetate butyrate sensing layer on the ITO interdigitated electrode arrays by screen printing process. The transmittance in the visible band and the capacitive response to the relative humidity ranging from 0% to 90% of the printed sensors were tested experimentally. The fabricated sensors showed a high transparency of 90.74%–92.29% and a linearity of 0.96 of capacitance response to relative humidity in the range of 0%–90%. Fabricated by the low-cost screen printing process which is widely used in display industry, the transparent sensors showed a great application prospect to be integrated on displays in smart devices.