Textile electrodes in capacitive signal sensing applications

This article introduces a capacitive measurement method for objective examination of textile sensor sensitivity within the frequency range associated with various biosignals. The proposed evaluation method is subsequently used to investigate biosignal sensing properties of a basic copper surface sensor and two selected textile sensors made from commercially available and commonly used conductive Shieldex and Elitex fibres. Experiment results indicate that the Elitex-based electrode is more suitable than Shieldex and copper surface electrodes. The signal attenuation of the Elitex electrode is lower by approx. 1-2 dB in comparison to the Shieldex electrode in the 0.5 Hz to 10 kHz frequency range. The copper surface electrode has slightly better signal transmission properties within low frequencies (<3 Hz), however these are not considered critical in biosignal sensing.