Flexible e-textile sensors for real-time health monitoring at microwave frequencies

Abstract

This paper reports on testing of the performance of SmartLife® e-textile material. In particular, the response of the integrated conductive pathways at microwave frequencies in the region of 9 kHz to 6 GHz is investigated for both biomedical sensing and signal transmission purposes. The experimental results confirm the viability of exciting the e-textile material at ISM microwave frequencies at mW powers for the purposes of wearable non-invasive sensing. Custom made flexible microwave sensors suitable for integration into smart e-textile fabric were tested in their ability to perform real-time body parameters monitoring, in particular the level and composition of perspiration. Gradual change in both the resonant frequency peak and amplitude was recorded in the 2-3 GHz frequency range with increased volume of fluid (50-350 μl) when in contact with a 5×8 mm2 sensor. This fabric with built-in textile sensors could serve as a platform for "high-tech designer outfits" for an advanced healthcare approach where real-time data on patient condition is transmitted wirelessly for immediate processing and corrective action if necessary. The novel sensor reported here was recently patented under milestone UK patent application number GB 2500000.