EGaIn liquid metal
Dickey and colleagues showed eutectic gallium-indium forms a thin skin that lets the liquid hold shapes in tiny channels.
Built / tested: stretchable wires
As reported in: Dickey, Chiechi, Larsen et al. (2008). Eutectic Gallium‐Indium (EGaIn): A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature. Advanced Functional Materials. doi:10.1002/adfm.200701216
Abstract only