Flexible, self-adhesive and eco-stable bioelectronics with dual-network phytic acid-based ionic hydrogel for biomechanical and physiological signal monitoring.

Seamless integration with biological tissues and environmental adaptability are essential for continuous health monitoring, yet conventional bioelectronics often suffer from mechanical mismatch, poor adhesion, and limited stability. Here, we develop a self-adhesive and environmentally resilient ionic hydrogel (PHS-PA) with exceptional conductivity, flexibility, and durability. Constructed from a dual network of polyvinyl alcohol (PVA) and zwitterionic poly(SBMA-co-HEMA), physically cross-linked by phytic acid (PA), PHS-PA exhibits strong tissue adhesion, high ionic conductivity (10.6 S/m), anti-freezing capacity, low water loss, and intrinsic antibacterial activity. Its relatively low piezoresistive sensitivity under small deformations, along with superior conformability and stable skin-electrode interfaces, makes it ideal as soft electrodes for reliable electrocardiogram (ECG) monitoring. Moreover, its wide strain/pressure detection range (0-400 %, 0-10 kPa) enables effective tracking of large-scale motions such as gait. This study presents a versatile hydrogel platform for next-generation wearable bioelectronics, enabling reliable real-time health monitoring even in harsh environments.