Aim is to provide an autarkic, wireless humidity and temperature sensors on a flexible substrate suitable to be integrated in smart textiles. This can be used for wearable devices but also in industrial textiles, e.g. for monitoring potential leaks (roofs, basins, etc) over large areas operating in a network. Such sensors will typically have a thickness below 1 mm and can be easily attached to surfaces. Methods developed in ubiquitous sensing lead to improved localisation capabilities of water leaks.