You could probably do it with some sort of Gallium alloy, safer than mercury and more conductive. But I seem to remember them being more viscous? Maybe you cou

You could probably do it with some sort of Gallium alloy, safer than mercury and more conductive. But I seem to remember them being more viscous? Maybe you could use some sort of Teflon coated radio-penetrable container and a peristaltic pump.