Once picked up, the microdroplet is attached sufficiently strongly to the cantilever to allow us to move the droplet to desired regions on the substrate and form well-defined contacts repeatably without the droplet detaching. This relatively strong adhesion is induced by the interaction between the surface oxide layer of EGaIn and the gold coating of the cantilever. At the same time, the oxide layer also prevents direct contact of the bulk liquid metal with gold; in the absence of this oxide layer (for example after exposure to hydrochloric acid vapor), EGaIn will alloy with the gold and the droplet will no longer be spherical (Supporting Fig. ). However, we do not rule out the formation of nano-cracks in the oxide layer which allows the EGaIn droplet to form a direct contact with the gold cantilever contributing to the strong adhesion.