High-Sensitivity and Low-Hysteresis Inter-digital Type Capacitive Humidity Sensor on Glass Substrate by Aerosol Deposited BaTiO_3

摘要

Aerosol deposition (AD) is a shock-loading solidification ceramic film preparation technique exhibiting the advantages of room-temperature operation and highly efficient in film growth. Hygorscopic film which has a super mesoporous structure exhibits high sensitivies and fast response in humidity sensing. Our objective is to verify the feasibility of using AD by depositing BaTiO_3 films on a glass substrate with a Pt interdigital capacitor. Humidity sensing performances were evaluated by 400°C annealing temperature and 0.1-10 μm thickness of BaTiO_3. Films treatment in the thickness of 1.5 urn achieved excellent sensitivies in 178.6 ± 7.3 pF/%RH respectively. The surface hydrophilicity, pore volume, and open-pore ratio were analyzed as critical factors of the thickness related humidity sensing effects, and physical modeling exhibited an expanded humidity detection range, enhanced water vapor adsorption and desorption, and improved sensitivity to humidity.