Flexible Temperature Sensor Integration into E-Textiles Using Different Industrial Yarn Fabrication Processes

Abstract

Textiles enhanced with thin-film flexible sensors are well-suited for unobtrusive monitoring of skin parameters due to the sensors' high conformability. These sensors can be damaged if they are attached to the surface of the textile, also affecting the textiles' aesthetics and feel. We investigate the effect of embedding flexible temperature sensors within textile yarns, which adds a layer of protection to the sensor. Industrial yarn manufacturing techniques including knit braiding, braiding, and double covering were utilised to identify an appropriate incorporation technique. The thermal time constants recorded by all three sensing yarns was <10 s. Simultaneously, effective sensitivity only decreased by a maximum of 14% compared to the uncovered sensor. This is due to the sensor being positioned within the yarn instead of being in direct contact with the measured surface. These sensor yarns were not affected by bending and produced repeatable measurements. The double covering method was observed to have the least impact on the sensors' performance due to the yarn's smaller dimensions. Finally, a sensing yarn was incorporated in an armband and used to measure changes in skin temperature. The demonstrated textile integration techniques for flexible sensors using industrial yarn manufacturing processes enable large-scale smart textile fabrication.

Printable, Highly Sensitive Flexible Temperature Sensors for Human Body Temperature Monitoring: A Review

“…d Photo of the fabricated device [ 184 ]. e Concept of the flexible temperature sensor embedded within the fibres of a textile yarn [ 185 ] …”

“…Due to its high consistency, it is very suitable for non-existent monitoring of skin temperature, which significantly benefits patients and medical staff. Lugoda et al [ 185 ] used different industrial yarn fabricating processes to integrate flexible temperature sensors into fabrics, and studied the sensing effect of embedding flexible temperature sensors in textile yarns. The bending resistance and repeatability of the temperature sensor embedded in the yarn are verified.…”

An investigation of temperature-sensing textiles for temperature monitoring during sub-maximal cycling trials

“…It should be noted that the step-response time of the temperature sensing E-yarns were not investigated in this work. Previous studies on similar sensors [34] have shown these step response times to be very short, with the longest times reported being on the order of seconds.…”

Smart Socks and In-Shoe Systems: State-of-the-Art for Two Popular Technologies for Foot Motion Analysis, Sports, and Medical Applications

“…Various designs have been proposed for temperature monitoring with smart socks, both for diabetic and for healthy patients. Concerning the diabetic ones, temperature sensor integration technology in smart textiles [55] and TSS (temperature-sensing socks) technology was proposed, which is able to detect temperature variations in the feet. These temperature variations are good predictors of foot ulceration in diabetics, a condition that can lead to complications, even to amputation.…”