Comparison of Textile Resistive Humidity Sensors Made by Sputtering, Printing and Embroidery Techniques

This paper presents various constructions of flexible textile humidity resistive sensor prototypes which can be used in textronic clothing applications and can be easily integrated with fabric. They can be also used as sensors applied to sheets in hospitals and nursing homes, as well as in special medical clothing, especially for protecting elderly people. The author describes a method of manufacturing such sensors by three different techniques, such as embroidery, printing and sputtering (PVD). Also presented are electrical properties of the textile sensors under various environmental conditions. The resistance of the sensors was studied in a wide range of humidity, from 30 to 90%, and at temperatures of 30 °C and 40 °C. The author then chose the right type of textile substrate on which the sensors should be made. A microscopic examination of the upper electroconductive layer of the prototype sensors was also conducted. These novel methods of sensor creation for humidity measurement on flexible textile substrates and their comparison could be used for clothing functionalisation.