Abstract
Polystyrene(PS) thin films used as a material for absorbing water vapor were formed by plasma polymerization, providing chemical resistance and rigidity due to the network structure of the polymer. An Au thin film 120 Å thick was deposited on the surface of the PS thin film, sufficient to transport water vapor. Parallel plate capacitors were made in the form Au-PS-Al, and were used as capacitive humidity elements. Elements with a PS film thickness of about 2000 Å had a response time of 1 to 2 seconds, and PS thin film capacitors with these humidity characteristics are suitable for use as fast-response humidity elements.