Interfacial interaction-induced super-wettability of gallium-based liquid metals: a review

This review summarizes the super-wettability and wettability-related applications of gallium-based liquid metals (GLMs) induced by interfacial interactions between GLMs and substrates. In conventional studies, high surface tension and surface oxides limit the wetting and spreading of liquid metals (LMs) on various substrates. Many studies on LMs have focused on interfacial interactions to achieve super-wettability, which are mainly categorized into two types of interactions: physical and chemical. Physical interactions include capillary force, electrical stress and physical adhesion. These are mainly represented in operations including treatments of substrate, physical covering, electric field actions and forced wetting. Alternatively, chemical interactions mainly involve metal bonds, ligand bonds and hydrogen bonds. Metal bonds are the most common and essential because GLMs can react with metal substrates and form intermetallic compounds (IMCs). Metal bonds can also combine chemical/electrochemical reactions to make GLMs exhibit super-wettability on substrates. Concerning the influence of these interfacial interactions, GLMs with super-wettability can expand application prospects in the fields of electrochemical energy storage and conversion and flexible self-healing electronic devices. Interfacial interactions are key factors to induce super-wettability between liquid metals and substrates, which mainly involve physical and chemical interactions.