Water-Enhanced Adhesive Interface for High-Quality Physiological Signal Monitoring in Skin-Device Integration

Flexible wearable electrodes play a critical role in establishing a stable and high-performance skin-device interface for human health monitoring. However, the signal quality of conventional electrodes is significantly compromised by sweat-moistened skin, leading to a reduced signal-to-noise ratio (SNR) and limiting their capacity for long-term monitoring. To solve this problem, a sweat-adaptive polymer electrode PEDOT:PSS-PMVEMA (PPMA) is proposed, which demonstrates superior adhesion properties compared to conventional electrodes, with a vertical peel-off strength of ≈60 N/m. Unexpectedly, the adhesion of PPMA electrodes improves upon wetting with water. The shear strength between the PPMA material and porcine skin can be tuned within the range of 5.1 to 12.7 kPa by adjusting the amount of added water, thereby enhancing their adaptability to perspiration while preserving a stable SNR. The PPMA electrode patch can be customized in size and shape to suit different recording tasks, including electroencephalography, electrocardiography, and electromyography. Combined with an in-house developed wireless recording system, these three most widely used and clinically significant physiological signals can be tracked continuously with high quality for up to 12 h. In the future, PPMA holds great potential for applications in telemedicine and smart healthcare.