Deflection Analysis of Micro Cantilever Due to Moisture Adsorption

Abstract

By exposing a micro cantilever which is composed by different two materials to vapor atmosphere, slight deflection of micro cantilever due to humidity change can be observed. As increasing relative humidity, the micro cantilever composed by Au and Si3N4 multi layer films bends slightly toward the side of Si3N4 thin film. When the both sides of micro cantilever is composed by the same material, no deflection can be detected. The micro cantilever has a differential sensitivity to moisture adsorption on to each surface of the micro cantilever. Based on activation energy at nucleation of moisture cluster, deflection mechanism of the micro cantilever can be analyzed. It is capable to apply the micro cantilever as a humidity sensor.