Spider-silk-inspired dry electrode keeps wearable biosignals steady during stretch

Wearable devices need electrodes that can capture weak bioelectrical signals reliably while the body moves. Conventional silver/silver chloride electrodes often use conductive gels, which can dry out, irritate the skin, and limit long-term use. Gel-free alternatives can avoid these problems but may produce high-impedance, drifting, or motion-sensitive signals.

Researchers from Soochow University and collaborating institutions developed a stretchable dry electrode called AAS. It embeds silver nanowires and silver chloride nanoparticles in a soft elastomer. The nanoparticles are arranged along the nanowires. Inspired by spider silk, this “bead-on-string” structure combines ion-electron signal conversion sites with continuous electrical pathways. The optimized electrode achieved a skin-electrode impedance of 49 kΩ at 10 Hz, tolerated stretching to 400% strain, and showed stable resistance up to approximately 370% strain. After 500 cycles of 100% stretching, its impedance changed by only about 1.2-fold.

In non-invasive volunteer tests, the electrode recorded ECG, EMG, EOG, and EEG signals, retaining clear cardiac waveforms during walking. In a personalized demonstration involving one participant, an artificial-intelligence model classified four gaze directions from the electrode’s eye-movement signals with 98% accuracy. The signals were then used to control a Pac-Man game in real time.

The work, titled “Bead-on-string Ag/AgCl heterostructures enable nonpolarizable stretchable dry electrodes for long-term, high-fidelity electrophysiological interfaces” was published in Soft Science on July 9, 2026.