Nondestructive Testing and Evaluation of Smart Textile Sensors using Embedded Systems

The integration and coating with conductive elements allows the use of textiles as flexible sensors for physical and chemical quantities. These conductive textiles combine the mechanical properties of the carrier material with the electrical characteristics of the conductive elements. Due to inhomogeneities in manufacturing as well as the influence of ageing factors, such as mechanical or chemical stress, the accuracy of these sensor systems suffers over the product lifespan. In this paper, we present a comprehensive evaluation system to detect these inhomogeneities in the textile material and measure the influence of the most common ageing factors. We compare several measuring methods from electrical engineering, medicine and chemistry in order to select the best methods for wear detection in conductive textiles. Using test stands for accelerated ageing, the ability to measure these effects was also successfully demonstrated on embedded systems. This means that the next generation of smart textile sensors systems are able to compensate for inhomogeneities in the production process as well as wear and tear due to ageing by itself. Thus, a reduction of waste, a longer lifetime of the sensor systems as well as improved accuracy can be achieved.