Gold–Titanium Nanofilm Textile Dry Electrodes for Electrocardiogram Monitoring: Electrical, Electromechanical and Skin‐Phantom Evaluation

Ag/AgCl gel electrodes are the clinical standard for electrocardiogram (ECG) recording, but at the skin–electrode biointerface, gel drying and skin irritation limit accurate recording over several days. To explore gel-free alternatives, we sputtered gold over a titanium adhesion layer onto serpentine textile dry electrodes and examined how Au:Ti thickness affects electrical, electromechanical and simulated ECG performance. Four variants (50:10, 80:15, 100:15 and 100:20 nm) were characterised by scanning electron microscopy, collinear four-probe measurement and mandrel bending, and the textile geometry by tensile testing. The two best coatings were then compared with commercial Ag/AgCl electrodes on a two-layer skin phantom using impedance measurements and simulated ECG acquisition. All coatings lowered sheet resistance relative to the uncoated textile, with the 80:15 nm variant giving the lowest value. The 100:20 nm variant was the most stable under bending and showed the least post-bend surface damage. The serpentine track did not significantly reduce bend-induced resistance change. On a porous phantom, both dry electrodes recorded identifiable ECG waveforms; mean signal-to-noise ratio was 24.4 ± 0.2 dB for Ag/AgCl, 15.9 ± 3.9 dB for 80:15 nm and 18.4 ± 0.5 dB for 100:20 nm (p = 0.061). Au:Ti-coated textiles are a feasible, gel-free biointerface for conformable ECG electrodes, but motion, durability and on-skin testing are required.