Oxide-Free Actuation of Gallium Liquid Metal Alloys Enabled by Novel Acidified Siloxane Oils

• DOI: 10.1021/acs.langmuir.6b03501
• Publication Date: 2016-11-07T17:36:22Z
• Authors: Sarah Holcomb; Michael Brothers; Aaron Diebold; William Thatcher; David Mast; Christopher Tabor; Jason Heikenfeld
• Keywords: Liquid metal; Siloxane; Passivation

Electrowetting and electrocapillarity of liquid metals have a long history, recent explosion renewed interest. Liquid electromagnetic properties surface tensions (>500 mN/m) that enable new forms reconfigurable devices. However, the only nontoxic option, gallium alloys, suffer from immediate formation semirigid oxide. Although acids or electrochemical reduction can remove this oxide, these approaches surround alloy in fluid is also electrically conducting, diminishing effectiveness precluding electrowetting actuation. Reported here are acidified siloxanes prevent oxide formation. Importantly, siloxane oil associatively incorporates hydrochloric hydrobromic acids, insulating, chemically stable, removes etching byproducts (including water), allows robust electrowetting. This work opens up opportunities for metal reconfiguration, fundamental interest due to unexpected chemical stability their application other materials surfaces.