A Novel Sensing Textile Antenna with Polyimide for Humidity Detection

This paper proposes a cost-effective and a compact humidity sensing textile antenna with polyimide in sensor applications. We present novel design of an aperture coupled patch (ACP) which is coupled to an interdigitated capacitor (IDC). Because of low mutual coupling, during the sensing process the textile antenna is not detuned out of its operational bandwidth and performance is not compromised by the presence of the sensor. The sensing function is deposited as a superstate with polyimide film and a textile felt as the main substrate. Due to polyimides high sensitivity toward humidity, any change in humidity is detectable through the change in the material permittivity of polyimide and changes in the resonant frequency of flexible antenna. The fabrication design of IDC wearable antenna is present. Furthermore, the advantage of the sensor geometry can be independently optimized without affecting the radiation pattern