An ionic liquid ion source can include a microfabricated body including a base and a tip. The microfabricated body can be formed of a porous metal compatible (e.g., does not react or result in electrochemical decaying or corrosion) with an ionic liquid or a room-temperature molten salt. The microfabricated body can have a pore size gradient that decreases from the base of the body to the tip of the body, so that the ionic liquid can be transported through capillarity from the base to the tip.