Hydrogels possess mass-permeable, ultra-soft, and low-impedance material properties. These characteristics make functionalized hydrogel-based stretchable bioelectronics well-suited for achieving high-quality, stable, long-term tissue-device interfaces. For example, a highly conductive and adhesive hydrogel engineered with nanomaterials was introduced (^(ⅰ)Advanced Materials, 2024), enabling efficient electroceutical applications. Furthermore, we are advancing both material systems and fabrication techniques that allow for precise patterning and seamless integration of functionalized hydrogels with flexible and stretchable bioelectronics, crucial for optimizing the device performance (^(ⅱ)Science Advances, 2021; ^(M)Science Advances, 2024). Such integration enhances device functionality, enabling real-time health monitoring through advanced sensing capabilities. These innovative technologies hold great promise for a wide range of applications, including rehabilitation, long-term health monitoring, point-of-care treatment, and disease prevention.