I. Introduction
Among other gases, the detection of relative humidity (RH) is crucial in air quality monitoring, food storage, agriculture, meteorology and biodetection [1]. It is also a key parameter in the control of processing industries, as water is a common interfering molecule in the capture and detection of other gases (e.g. CO2 detection) [2]. Different transduction mechanisms have been reported for gas detection, such as electrical conductivity, optical or acoustic responses [3]. We present here a humidity sensor based on the magnetoelastic resonance (MER) phenomenon, which fit the criteria of compactness, low cost, fast response, stability and high sensitivity, and have the advantage of operate remotely and contactless.