Interfacial Engineering for Highly Stable and Stretchable Electrodes Enabled by Printing/Writing Surface‐Embedded Silver and Its Selective Alloying with Liquid Metals

Abstract Even though intrinsically stretchable liquid metals (LMs) have been widely used in the stretchable electrodes for improving the stretchability, it is still challenging to achieve stable interfaces in these electrodes. A usual approach of adhering the LMs on a substrate is to modify the LMs with an organic surfactant, which is easily ruptured under a dynamic deformation. Herein, a surface‐embedded silver and its selective alloying of LMs are reported to address this problem. Typically, the surface‐embedding structure and the alloying interaction are both robust and stretchable, enabling the high interfacial stability during deformation (the ability to resist peeling, scratching, and sonication). And the cracked silver layer under tensile strains can be well bridged by LMs, enabling the good conducting stability during deformation (resistance change of 0.076 at 50% strain, 0.18 at 100% strain, and 0.4 at 200% strain). It is noted that this interfacial engineering can be facilely organized by directly printing or writing, which is convenient for preparing customized electrodes and circuits. At last, a light‐emitting diode array and a drone remote controller are assembled using the stretchable electrodes, showing their advantages in practical application.