An Intrinsically Stretchable Hybrid Electronic via Printing‐Enabled Scalable Liquid Metals Patterning for Wearable Pulse Monitoring

ABSTRACT

Flexible hybrid electronics (FHEs) have widespread potential applications in wearable sensing, in particular for practical monitoring of human pulses. However, FHEs suffer from insufficient conformation with complex and dynamic skin surfaces. Resulting motion artifacts severely limit the long‐term reliability of pulse monitoring under various exercise conditions. This underscores the importance of developing system‐level mechanical stretchability. Herein, we propose a technical route to fabricate intrinsically stretchable hybrid electronics via liquid metals (LMs) patterning. Taking advantage of the selective wettability and microoxidation of LMs, a semicured polymer is used as a soft transfer medium to achieve high‐fidelity LMs patterning at a device yield of 96.3%, with the resolution of 100 µm. Importantly, this method can be scaled up through compatibility with mature roll‐to‐roll flexible circuit printing technology. Our method enables the fabrication of stretchable FHEs, which can form a conformal interface with the skin and undergo adaptive deformation during motion (sitting, walking, and running), allowing real‐time accurate acquisition of pulse signals by photoplethysmographic sensing. Our work provides a robust technical pathway for advancing FHE systems and boosts the development of wearable pulse monitors.