Self-Healable and Conductive Hydrogel Nanocomposite with High Environmental Stability for Electromagnetic-Interference-Free Electrocardiography Patches

Electrocardiogram (ECG) sensor is emerging as an essential medical device for diagnosing various cardiovascular diseases in modern people. Conventional ECG sensors have investigated by several researchers, but they still have significant issues of discomfort in wearing, easy swelling, poor electrical conductivity, and signal inaccuracy. Here, we demonstrate a hydrogel nanocomposite-based ECG sensor patches, monolithically integrated with a hydrogel-based biocompatible electrode and an electromagnetic interference (EMI) shielding layer in a single unit. The developed device with low impedance (20 kΩ) exhibited excellent mechanical properties including adhesion force (35.8 N m⁻¹), multiple detachability (5 times), stretching/twisting stability and self-healing characteristic. The ECG sensor displayed superior long-term humidity stability for 30 days, showing superior biocompatibility. Finally, the ECG patch with high EMI shielding property monitored human vital signal and pulse rate changes in real-time.