Preliminary Study on Textile Humidity Sensors

Determination of relative and absolute humidity is essential for industrious, in-home, healthcare and a number of other applications. Although there is a large variety of commercial sensors and advanced R&D developments, some specific applications require solutions that are flexible, relatively low-cost, simple in production, reliable and cover large areas. Some innovative solutions are brought by smart textiles - the field with great potential in areas facing challenging requirements and combine different disciplines and technologies. Smart textiles have already convinced in their potentials for sensor development and opportunity of bringing improvements to different aspects in construction, operation, physical or other properties. This report presents a preliminary study on the concept of a textile humidity sensor, its design and development issues cohered with particularities of further applications. Several designs of the sensor have been implemented by embroidery on a textile substrate using conductive yarns. In order to achieve efficient operation of the sensor with available materials and technologies, investigations on the choice of the appropriate design of the prototype including the specific pattern for the capacitor embroidery, yarns and substrate materials, have been performed and solutions for improving the initial prototype of the sensor are suggested.