NeuroTex: Functionalized Hybrid Polymer–Metal Textile for Soft, Robust, and Dry Auricular Neural Interfaces

Wearable bioelectronics would benefit from dry, easy-to-apply electrodes for sensing physiological signals. Bioelectronic interfaces must maintain high conductivity, low electrode-skin impedance, and reliable coupling between the electrode and skin under sweat, motion, and prolonged use. Metallic textiles offer good conductivity and stable connections but are hydrophobic, prone to cracking and oxidation, and dependent on conductive gels to achieve the low impedance required for low-amplitude electrophysiological signals. Here, we introduce NeuroTex, a commercially available silver nanowire textile that is PEDOT:PSS-functionalized to improve the electrode-skin-electronics interface. The PEDOT:PSS coating reduced the area-normalized resistance of the textile by almost 50%, suppressed silver oxidation in phosphate-buffered saline, and lowered the contact impedance by more than 85%. Mechanical evaluations under torsion, stretching, bending, and low-force fatigue confirmed the preserved fiber integrity and intact electronic connectivity. Furthermore, the soft and hydrophilic properties of the coating enhanced the conformal skin interfacing. Integrated into an in-ear monitoring platform, NeuroTex enabled multimodal biosignal recordings of in-ear electroencephalography (ieEEG), electro-oculography (ieEOG), electromyography (ieEMG), and electrocardiography (ieECG). Reliable acquisition of the technically demanding ieEEG signal was achieved, demonstrating alpha-modulation responses comparable to those of gel-based electrodes. ieEEG recordings recorded over several hours captured distinct sleep patterns to further confirm stable performance during natural sleep. These results establish NeuroTex as a gel-free, mechanically resilient, and electrochemically stable interface suitable for wearable physiological monitoring.