High-Sensitivity and Low-Hysteresis Inter-digital Type Capacitive Humidity Sensor on Glass Substrate by Aerosol Deposited BaTiO3

E.S. Kim, Z.J. Wang, C. Wang, Z. Yao, J.G. Liang, N.Y. Kim
Kwangwoon University,
Korea

Keywords: humidity sensor, aerosol deposition, BaTiO3 films, hygroscopic film

Summary:

A high-sensitivity and low-hysteresis inter-digital type capacitive humidity sensor is fabricated using Aerosol deposition (AD) of BaTiO3 films. Aerosol deposition (AD) uses shock-loading-solidification preparation mechanism as a novel ceramic film preparation technique, exhibiting the advantages of room-temperature operation and highly efficient film growth. AD is utilized to deposit BaTiO3 films on a glass substrate with a Pt inter-digital capacitor to perform sensing performance by post-annealing at effective temperatures of 500℃. The hygroscopic BaTiO3 film aerosol deposited with BaTiO3 powder has a super mesoporous structure – shows excellent hysteresis under a wide humidity sensing range with good long-term stability. The 1.5-μm-BaTiO3 film exhibited excellent humidity sensing properties, a quick response and recovery. Finally, a good temperature-independent and stable capacitance value of inter-digital type capacitive humidity sensor is a sufficient value for use as a reliable humidity sensor in various applications.