Ni@Sn core–shell structured liquid metal magnetic suspensions for high-sensitivity stretchable electronics and tunable magnetic response

Abstract

Room temperature liquid metals, such as galinstan, have emerged as promising candidates for stretchable and deformable electronics due to their superior fluidity and electrical conductivity. While incorporating metallic fillers can impart magnetism, the interfacial alloying reaction between galinstan and metals often compromises the stability and properties of the resulting composites. In this study, an in situ chemical reduction plating method is proposed to modify nickel (Ni) particles at room temperature. By depositing a tin (Sn) shell onto the Ni surface, Ni@Sn core–shell nanoparticles are synthesized and subsequently dispersed into a liquid metal (LM) to form liquid metal-based Ni@Sn magnetic suspensions (LMNSs). First principles calculations of the interfacial binding energy and electron localization function (ELF) elucidate the interfacial stability and bonding mechanism within the Ni@Sn structure. The Sn shell effectively shields the Ni core from corrosion by the liquid metal matrix. Flexible circuits fabricated from the LMNS composite exhibit outstanding electromechanical performance, including a high gauge factor (GF = 9.06 at 200% strain) and excellent stretchability (up to 200%). Furthermore, the LMNS demonstrates significant potential for applications in supercooled soft intelligent sensing, patterning, and magnetic manipulation. This work provides a facile strategy for the development of magnetic liquid metals with appealing properties and broad application prospects.