Stretchable and self-adhesive ovalbumin-reinforced double-network polyacrylamide/gellan gum conductive hydrogel for...

With the advancement of skin bioelectronics, hydrogel-based wearable devices have broadened their applications in health monitoring and strain sensing. However, their use is hampered by inadequate mechanical properties, a limited sensing range, and restricted environmental sensitivity. In this study, we draw inspiration from the hierarchical structure and unique interaction mechanism of ovalbumin (OVA) to report the synthesis of a multifunctional dual-network ionic conductive hydrogel (ICH). This hydrogel is reinforced thermally by self-assembled OVA, a globular protein. The polyacrylamide/gellan gum@OVA (PAM/GG@OVA) hydrogel has modulated framework that shows impressive mechanical properties: a fracture stress of 1.12 MPa, toughness of 582.77 kJm^-3, stretchability of 1087 %, and adhesiveness of 8.22 kPa. Additionally, they maintain a high electrical conductivity of 0.43 S/m, making them suitable for real-time strain sensing applications. These characteristics allow the hydrogel to function as a multifunctional, durable wearable device, boasting excellent sensitivity with a gauge factor of 13.67 and a quick response time of 150 ms. When utilized as a flexible strain sensor, the hydrogel effectively detects a wide range of human movements, from subtle vocal cord vibrations to large joint motions, while ensuring stable adhesion to the skin. Furthermore, the hydrogel is capable of accurately recognizing and replicating hand written text. By investigating the reinforcing properties of ovalbumin, these findings lay the groundwork for the sustainable development of hydrogel-based wearable electronic devices that are durable, environmentally adaptable, and capable of multi-sensory responsiveness.