Marangoni‐Driven Sintering of Liquid Metal Droplets for Strain‐Insensitive Flexible Electronics

ABSTRACT Microengineering of liquid metal (LM) micro/nano‐droplets into conductors is essential for the development of stretchable electronics. However, the spontaneous coalescence of LM droplets within the elastomer film is hindered by their surface shells. Herein, a Marangoni‐driven self‐sintering approach is proposed for fabricating stretchable electronics. By leveraging the Marangoni effect induced through rapid non‐solvent volatilization, gradient droplet sedimentation is formed, which increases the sintering force on sintering LM droplets without any post‐activation processes (e.g., mechanical force, laser ablation or acoustic field). The resultant elastic film exhibits exceptional conductivity (1.1 × 10 5 S/m) at a low LM content (17 vol%). Remarkable strain‐insensitive electrical behavior (R/R 0 = 1.5 at 1250% strain) can be achieved owing to the complementary effect of the inner LM droplets during straining. This interface‐force‐regulated self‐sintering strategy provides a novel paradigm for developing LM‐based flexible electronics with significant potential for wearable sensors, intelligent heating systems, and electromagnetic interference shielding applications.