Journal Article Biocompatible Materials CH46OC8YV4 Gallium Research Support, Non-U.S. Gov't angle-resolved photoemission spectroscopy bidirectional stiffness tuning correlated electron systems density functional theory dynamical mean-field theory electronic reconstruction epitaxial oxide heterostructures ferroelectricity flexible thermoelectric devices gallium graphene interface control quantum tunneling robotic skins ruthenates sensory augmentation stiffness tuning supercooling of gallium terrace edges transformative electronics tunable pressure sensors ultrathin oxide films